Fix Ubunut Unity, compiz

Fix errors in ubuntu, unity, compiz

When the Desktop is frozen and unusable, compiz killed or shut down in some unusual way you can restart it to gain some/full functionality.

Login to a text shell (tty-1 to tty-6) by pressing STRG-ALT-1 to -6.

> DISPLAY=":0.0" compiz --replace

or

> DISPLAY=":0" compiz --replace

For restarting the GUI (because you can not reboot while someone else - you - is logged in)

> DISPLAY=":0.0" unity --replace