Added Channel::RegisteredHandler module instead of messing with Channel singleton class
Added weak kwarg to Channel#register
Start using Ref to provide WeakRef implementation
Add 'ref' dependency to gemspec
Made convenience_spec test forwarding instead of testing end behaviour

--HG--
extra : amend_source : 5a46d93936dec03bfb9d846569573bf9aac6d416
Added Channel.forget

--HG--
extra : amend_source : 70858e8122aca79021300e5f1ecc3098906944ed