Redirect dpkg -l stderr to /dev/null

Fixes bug 1211413

Change-Id: I33a7e1e8fb3755c69ca0570e333e4908cb6f3da4
.conf suffix for the horizon config on Fedora

On Fedora by default the *.conf imported only from
the /etc/httpd/conf.d/.

Changing the default config name to horizon.conf with all
distribution in order to have a simple logic.

Change-Id: I08c3e825f697640fd73ac1f9c569f313abc3c04f
Remove useless sources.list

Change-Id: I136b568f04f1de35556aa7c3d546c44402254eef
Merge "Redirect dpkg -l stderr to /dev/null"
Merge ".conf suffix for the horizon config on Fedora"
Merge "Remove useless sources.list"