start*/enter-chroot: Make sure options with missing arguments are detected.

Mark the end of user specified parameters with "".

Makes sure commands like `sudo startcli -u` fail instead of outputing
confusing messages like `user exec not found`).
Install lts-saucy xorg on Haswell for precise release. For better support of the intel driver.
Fixed remarks on the previous commit, added xorg config file to enable sna accelaration and TearFree is true. This should be enough to enable fbc again for the supported distro releases on haswell.
Renamed 20-intel.conf to 20-intel-crouton.conf, and enabled fbc when 20-intel-crouton.conf is present.
Remove 20-intel.conf
Removed duplicate code, removed kali check, added some more comments in the code. Also fixed name for the link to 20-intel-crouton.conf.
Added xterm and X11-apps to precise release. Some cosmetic changes proposed by drinkcat
Merge branch 'master' of github.com:divx118/crouton