Fixed copyright clauses.

Fixed copyright clauses.

Checked that copyright notices are properly set up as according to:

http://www.gnu.org/licenses/gpl-howto.html

Corrected where they are not. Note that one or two-line fixes do not
count as copyrightable assets.

Additionally, fixed a minor indentation issue in chsmack.c.
(cherry picked from commit 7b41f3cff96755146539f74a8c780ac9bbe71b36)