Fixed links to Gnome lib docs in POD; closes RT#86968
Remove FSF address and shorten license notice

- Reference toplevel LICENSE file in license notices at the top of all
  of the *.xs files for full license text and correct address to FSF
Update copyright date in files with PL_na changes
Gnome2.pm: Update copyright, shorten license notice

- Refer users to top level LICENSE file
Created %meta_merge which follows v2 of CPAN::Meta::Spec

- %meta_merge is used to pass META_MERGE values to EU::MM and
  CPAN::Meta; these populate META.[yml|json] and MYMETA.[yml|json]