[bug-mailutils] Copyright updates

[Jeff Bailey]

My brain hurts.

Every Makefile.am now has the correct copyright year information
(verified with cvs annotate), and has license information.

Please remember to start touching the year tomorrow (Unless you're in
Australia where it already is tomorrow *grin*) when you're updating
files.  I think we've been better about it with the .[ch] files so I
shouldn't need to do the annotate on all of them.

Tks,
Jeff Bailey