Pass -x and -v set options from main.sh to prepare.sh (useful for debugging).
add cinnamon target

Fixes #220
add -t cinnamon to startcinnamon
move cinnamon target check to beginning of file
Properly check if a package is installed or not.
dpkg-query -s <pkg> returns 0 even when status is "deinstall ok config-files".
Instead, check if the full "Status" string starts with either "install" or "hold".
Replace virtual package names by actual ones.
Remove package with remove instead of autoremove. Run autoremove at the end of post-common.
autoremove is not supposed to take parameters in the first place, and fails to remove uneeded dependencies of the specified packages when --purge is set.
Leverage on autoremove to remove packages that are only needed for building.
This makes the installation faster as we do not need to constantly install/uninstall packages.
Simple XInput 2 client, for use in croutonpowerd and croutonwheel.
Make croutonpowerd use croutonxi2event:
 - No need to use xprintidle (orphan package)
 - Ping immediately on keypress (instead of having to wait up to 2 seconds)
 - Polling time can be reduced significantly
Make croutonwheel use croutonxi2event:
 - Parsing logic is simplified (output on a single line).
 - Less "garbage", croutonxi2event only outputs XInput events.
 - No hack needed to hide xinput window.
Use dpkg-query -l instead of dpkg-query -W.
Rewrites part of xi2event.c that were directly copied from xinput.
Still looks very similar as this is essentially the only way to do things.
Fixes after review.
Fixes after review.
Better xinput mask allocation.
fix cinnamon target in Debian

There are no packages in jessie for Cinnamon, and no ARM builds for Cinnamon in Debian at all right now.
fix help and icon theme for cinnamon
croutonpowerd: Test if $xi2pid is empty before checking the process status.
install_mirror_package function for Ubuntu/Debian: fetch package from a different release.