add possibility to select filesystems

[Karl-Philipp Richter]

Currently it's only possible to display a minimal set of filesystem or all filesystems. It'd be nice to be able to select the filesystems to be displayed in the filesystem overview of `gnome-system-monitor`.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: gnome-system-monitor 3.15.91-0ubuntu1
Uname: Linux 4.0.0-040000-generic x86_64
NonfreeKernelModules: zfs zunicode zcommon znvpair zavl
ApportVersion: 2.17.2-0ubuntu1
Architecture: amd64
CurrentDesktop: Unity
Date: Wed Apr 22 10:08:34 2015
EcryptfsInUse: Yes
InstallationDate: Installed on 2015-04-02 (19 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Beta amd64 (20150326)
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-system-monitor
UpgradeStatus: No upgrade log present (probably fresh install)

[Sebastien Bacher (seb128)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. The issue you are reporting is an upstream one and it would be nice if somebody having it could send the bug to the developers of the software by following the instructions at https://wiki.ubuntu.com/Bugs/Upstream/GNOME. If you have done so, please tell us the number of the upstream bug (or the link), so we can add a bugwatch that will inform us about its status. Thanks in advance.

[Francis Chin (chinf)]

Perhaps upstream bug https://bugzilla.gnome.org/show_bug.cgi?id=378605 would solve this?