Update to version 1.2.0
    
    New Functions:
      * Modulemd.objects_from_file()
      * Modulemd.objects_from_string()
      * Modulemd.dump()
      * Modulemd.dumps()
      * Modulemd.Defaults.new_from_file()
      * Modulemd.Defaults.new_from_string()
    Deprecated Functions:
      * Modulemd.Module.new_all_from_file()
      * Modulemd.Module.new_all_from_file_ext()
      * Modulemd.Module.new_all_from_string()
      * Modulemd.Module.new_all_from_string_ext()
      * Modulemd.Module.dump_all()
      * Modulemd.Module.dumps_all()
    Bugfixes
      * Properly use G_BEGIN_DECLS and G_END_DECLS in headers
      * Assorted fixes for memory ownership in GObject Introspection
    
    Signed-off-by: Stephen Gallagher <sgallagh@redhat.com>