make all fails on centos 6.4

[James Kyle]

    git clone https://github.com/stackforge/fuel-main.git
    cd fuel-main
    make iso

produces:

yum -c /vagrant/build/mirror/centos/etc/yum.conf clean all
Loading "priorities" plugin
Config time: 0.011
Yum Version: 3.2.29
Error: File contains no section headers.
file: file://///vagrant/build/mirror/centos/etc/yum.repos.d/base.repo, line: 1
'-e \\n[proprietary]\n'
make: *** [/vagrant/build/mirror/centos/yum.done] Error 1

What's happening is the base.repo file contains invalid content. The literal '-e \n' being passed to echo is output to the file.

cat build/mirror/centos/etc/yum.repos.d/base.repo

-e \n[proprietary]
name = RHEL 6.4 - Proprietary
baseurl = http://download.mirantis.com/fuelweb-repo/3.2/centos/os/x86_64
gpgcheck = 0
enabled = 1
priority=1\n

I'm drilling down through the make & *.mk files and trying to figure out why. A first glance looked alright. I'll add more information as I discover it.

[Dmitry Pyzhov (dpyzhov)]

Sorry, but we support only Ubuntu as build server. It will be great to fix this issue, but we have no time right now.

Issue consists of two parts:
- strange behavior of 'echo' command
- yumdownloader does not download packages if they already installed on build machine. it can be fixed with chrooting yumdownloader database.