Compiz, redundant and outdated files cleanup:

Removed outdated NEWS files.
Removed outdated AUTHORS and ChangeLog files.
Removed plugins/freewins/COPYING - we do not need another copy of the GPL v2 here.
Removed another copy of the GPL v2 from plugins/workarounds.

This will reduce package sizes, download time and bring some order to chaos.

Approved by Didier Roche, PS Jenkins bot, Sam Spilsbury.