This commit updates all authorship and copyright information to include a
standard header that references the AUTHORS and CREDITS file. This standard
header was written by the Debian legal team at the request of Franck Joncourt.
Added the 'const' qualifier to function prototype variables where possible.
In addition, reduced some functions to file-scope with 'static' where possible.
Also made a few minor changes to remove extra whitespace, and fixed a bug
in create_fwknoprc() to ensure the new fwknoprc filehandle is closed.
