Created %meta_merge which follows v2 of meta-spec
Created %meta_merge which follows v2 of 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]
- Moved AUTHOR and LICENSE fields into %meta_merge
- CPAN::Meta::Spec explains fields and their allowed values
  (https://metacpan.org/module/CPAN::Meta::Spec)

GNOME/perl-Cairo,cpanxaoc/perl-Cairo,cpanxaoc/perl-Cairo,GNOME/perl-Cairo,GNOME/perl-Cairo