Code review comment for lp:~kamstrup/libunity/faves-enumerator

Looks good, just two minor issues:

1) libunity is inconsistent in method names to get singleton instance (get_instance vs get_default), I'd rather see us using get_default which is more common in gobject world.
2) it'd be nice to add `public bool contains (string id)`, to support 'in' operator.