Cleanup: use consistent copyright location, move descriptions

Order copyright immediately after the license block,
this was done almost everywhere with a few exceptions.

Remove authors from a few files (we had already removed "Contributors"
section however with old patches being applied this gets added back in).

Also move descriptive text into the doxygen comment block under \file.
In some cases remove the text as it was accidentally copied.

release/scripts/startup/bl_operators/object_align.py

@@ -1,5 +1,4 @@
 # ##### BEGIN GPL LICENSE BLOCK #####
-
 #
 #  This program is free software; you can redistribute it and/or
 #  modify it under the terms of the GNU General Public License