diff -ur a/Pinta/Pinta/Pinta.csproj b/Pinta/Pinta/Pinta.csproj
--- a/Pinta/Pinta/Pinta.csproj	2016-05-03 15:12:00.291374778 +0200
+++ b/Pinta/Pinta/Pinta.csproj	2016-05-03 15:12:09.453374915 +0200
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0">
-  <PropertyGroup>
+  <PropertyGroup><TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
     <ProductVersion>9.0.30729</ProductVersion>
@@ -73,14 +73,14 @@
     <Optimize>false</Optimize>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
   </PropertyGroup>
-  <PropertyGroup>
+  <PropertyGroup><TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <ApplicationIcon>Pinta.ico</ApplicationIcon>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="atk-sharp, Version=2.12.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f">
       <Package>gtk-sharp-2.0</Package>
     </Reference>
-    <Reference Include="Mono.Posix, Version=2.0.0.0, Culture=neutral, PublicKeyToken=0738eb9f132ed756, processorArchitecture=MSIL" />
+    <Reference Include="Mono.Posix" />
     <Reference Include="System" />
     <Reference Include="gtk-sharp, Version=2.12.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f">
       <Package>gtk-sharp-2.0</Package>
diff -ur a/Pinta/Pinta.Core/Pinta.Core.csproj b/Pinta/Pinta.Core/Pinta.Core.csproj
--- a/Pinta/Pinta.Core/Pinta.Core.csproj	2016-05-03 15:12:00.243374777 +0200
+++ b/Pinta/Pinta.Core/Pinta.Core.csproj	2016-05-03 15:12:09.427374915 +0200
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0">
-  <PropertyGroup>
+  <PropertyGroup><TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
     <ProductVersion>9.0.30729</ProductVersion>
@@ -55,7 +55,7 @@
     <CodeAnalysisRuleSet>AllRules.ruleset</CodeAnalysisRuleSet>
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="Mono.Posix, Version=2.0.0.0, Culture=neutral, PublicKeyToken=0738eb9f132ed756, processorArchitecture=MSIL" />
+    <Reference Include="Mono.Posix" />
     <Reference Include="System" />
     <Reference Include="gtk-sharp, Version=2.12.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f" />
     <Reference Include="System.Core" />
diff -ur a/Pinta/Pinta.Docking/Pinta.Docking.csproj b/Pinta/Pinta.Docking/Pinta.Docking.csproj
--- a/Pinta/Pinta.Docking/Pinta.Docking.csproj	2016-05-03 15:12:00.256374777 +0200
+++ b/Pinta/Pinta.Docking/Pinta.Docking.csproj	2016-05-03 15:12:09.436374915 +0200
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
+  <PropertyGroup><TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
     <ProjectGuid>{8467329A-1BDC-4F21-8349-3E484C185D14}</ProjectGuid>
@@ -9,7 +9,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>Pinta.Docking</RootNamespace>
     <AssemblyName>Pinta.Docking</AssemblyName>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    
     <FileAlignment>512</FileAlignment>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
@@ -42,7 +42,7 @@
     <Reference Include="glib-sharp, Version=2.12.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f" />
     <Reference Include="pango-sharp, Version=2.12.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f" />
     <Reference Include="Mono.Cairo" />
-    <Reference Include="Mono.Posix, Version=2.0.0.0, Culture=neutral, PublicKeyToken=0738eb9f132ed756, processorArchitecture=MSIL" />
+    <Reference Include="Mono.Posix" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="Classes\MouseTracker.cs" />
diff -ur a/Pinta/Pinta.Effects/Pinta.Effects.csproj b/Pinta/Pinta.Effects/Pinta.Effects.csproj
--- a/Pinta/Pinta.Effects/Pinta.Effects.csproj	2016-05-03 15:12:00.264374778 +0200
+++ b/Pinta/Pinta.Effects/Pinta.Effects.csproj	2016-05-03 15:12:09.432374915 +0200
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <PropertyGroup>
+  <PropertyGroup><TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
     <ProductVersion>9.0.30729</ProductVersion>
@@ -10,7 +10,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>Pinta.Effects</RootNamespace>
     <AssemblyName>Pinta.Effects</AssemblyName>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    
     <FileAlignment>512</FileAlignment>
     <FileUpgradeFlags>
     </FileUpgradeFlags>
@@ -58,7 +58,7 @@
     <Reference Include="gdk-sharp, Version=2.12.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f" />
     <Reference Include="glib-sharp, Version=2.12.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f" />
     <Reference Include="gtk-sharp, Version=2.12.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f" />
-    <Reference Include="Mono.Posix, Version=2.0.0.0, Culture=neutral, PublicKeyToken=0738eb9f132ed756, processorArchitecture=MSIL" />
+    <Reference Include="Mono.Posix" />
     <Reference Include="System" />
     <Reference Include="System.Core">
     </Reference>
diff -ur a/Pinta/Pinta.Gui.Widgets/Pinta.Gui.Widgets.csproj b/Pinta/Pinta.Gui.Widgets/Pinta.Gui.Widgets.csproj
--- a/Pinta/Pinta.Gui.Widgets/Pinta.Gui.Widgets.csproj	2016-05-03 15:12:00.266374778 +0200
+++ b/Pinta/Pinta.Gui.Widgets/Pinta.Gui.Widgets.csproj	2016-05-03 15:12:09.445374915 +0200
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0">
-  <PropertyGroup>
+  <PropertyGroup><TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
     <ProductVersion>9.0.30729</ProductVersion>
@@ -9,7 +9,7 @@
     <OutputType>Library</OutputType>
     <RootNamespace>Pinta.Gui.Widgets</RootNamespace>
     <AssemblyName>Pinta.Gui.Widgets</AssemblyName>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    
     <CodePage>65001</CodePage>
     <FileUpgradeFlags>
     </FileUpgradeFlags>
@@ -54,7 +54,7 @@
     <CodeAnalysisRuleSet>AllRules.ruleset</CodeAnalysisRuleSet>
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="Mono.Posix, Version=2.0.0.0, Culture=neutral, PublicKeyToken=0738eb9f132ed756, processorArchitecture=MSIL" />
+    <Reference Include="Mono.Posix" />
     <Reference Include="System" />
     <Reference Include="gtk-sharp, Version=2.12.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f" />
     <Reference Include="gdk-sharp, Version=2.12.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f" />
diff -ur a/Pinta/Pinta.Install.proj b/Pinta/Pinta.Install.proj
--- a/Pinta/Pinta.Install.proj	2016-05-03 15:12:00.270374778 +0200
+++ b/Pinta/Pinta.Install.proj	2016-05-03 15:12:09.441374915 +0200
@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="3.5">
+<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0">
 
   <!-- Set some paths -->
-  <PropertyGroup>
+  <PropertyGroup><TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <OutputPath>bin</OutputPath>
     <InstallPrefix>/usr/local</InstallPrefix>
     <BinDir>/usr/local/bin</BinDir>
diff -ur a/Pinta/Pinta.Resources/Pinta.Resources.csproj b/Pinta/Pinta.Resources/Pinta.Resources.csproj
--- a/Pinta/Pinta.Resources/Pinta.Resources.csproj	2016-05-03 15:12:00.270374778 +0200
+++ b/Pinta/Pinta.Resources/Pinta.Resources.csproj	2016-05-03 15:12:09.417374915 +0200
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0">
-  <PropertyGroup>
+  <PropertyGroup><TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
     <ProductVersion>9.0.30729</ProductVersion>
diff -ur a/Pinta/Pinta.Tools/Pinta.Tools.csproj b/Pinta/Pinta.Tools/Pinta.Tools.csproj
--- a/Pinta/Pinta.Tools/Pinta.Tools.csproj	2016-05-03 15:12:00.281374778 +0200
+++ b/Pinta/Pinta.Tools/Pinta.Tools.csproj	2016-05-03 15:12:09.449374915 +0200
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <PropertyGroup>
+  <PropertyGroup><TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
     <ProductVersion>9.0.30729</ProductVersion>
@@ -10,7 +10,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>Pinta.Tools</RootNamespace>
     <AssemblyName>Pinta.Tools</AssemblyName>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    
     <FileAlignment>512</FileAlignment>
     <FileUpgradeFlags>
     </FileUpgradeFlags>
@@ -54,7 +54,7 @@
     <CodeAnalysisRuleSet>AllRules.ruleset</CodeAnalysisRuleSet>
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="Mono.Posix, Version=2.0.0.0, Culture=neutral, PublicKeyToken=0738eb9f132ed756, processorArchitecture=MSIL" />
+    <Reference Include="Mono.Posix" />
     <Reference Include="System" />
     <Reference Include="System.Core" />
     <Reference Include="System.Xml" />
diff -ur a/Pinta/tests/Pinta.Core.Tests/Pinta.Core.Tests.csproj b/Pinta/tests/Pinta.Core.Tests/Pinta.Core.Tests.csproj
--- a/Pinta/tests/Pinta.Core.Tests/Pinta.Core.Tests.csproj	2016-05-03 15:12:00.330374779 +0200
+++ b/Pinta/tests/Pinta.Core.Tests/Pinta.Core.Tests.csproj	2016-05-03 15:12:09.422374915 +0200
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
+  <PropertyGroup><TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
     <ProjectGuid>{464F4A4F-C585-4BF4-9EAB-C95BDCFD9723}</ProjectGuid>
@@ -9,7 +9,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>Pinta.Core.Tests</RootNamespace>
     <AssemblyName>Pinta.Core.Tests</AssemblyName>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    
     <FileAlignment>512</FileAlignment>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">