Wirebird::Resource

A Wirebird::Resource object is either a Wirebird message (mailing list/forum/NNTP post), or a wiki page (this is not well supported yet, which is why I'm writing this in TWiki instead).

Under some circumstances, it can just be a glorified Email::Simple message that never gets stored, in which case it's only a Wirebird::Resource so it can use the shared mail-sending functions. This might need better segregation someday.

Resource creation needs some cleanup. It tries to be too smart in cases - creating a new Resource from an email text, or automagically loading one from the store if you give it enough information (a message-id, group/topic/page triple, etc.), and sometimes gets carried away.

Its MIME handling leaves much to be desired, too.