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)
Use strncpy() always copying labels.

Defence in depth and a good practice. Places an absolute limit
to the length copied.
(cherry picked from commit 0eee8f8b3efd153c5ef09c08244e189f0cda51a4)