Fix @glib:ref-func generation

Method was missing the proper return type which generated the Ref method but did not pass the check for the special Ref method handling in the generator. Also mark these return types as owned
Prefer methods over signals

When a method with the same name is found, then 'Event' is added to the signal's name. It seems that in most cases the method name should be preferred over the signal name. Also emit a warning tag, when a method is renamed, because these events should be renamed using the metafile manually.
Merge pull request #12 from xDarkice/master

Fix @glib:ref-func generation