Include preliminary `extends' support for Moose-like

Hooks can now properly register other hooks.  The new mooselike hook
currently registers the `extends' hook, which is pretty much the same
as the `require' hook right now.  Oh, and `with' shall be pretty
similar, too.  The only difference is it supports multiple roles to
inherit from.

Signed-off-by: Petr Šabata <contyk@redhat.com>