WoW:Sky (AddOn)

--[[
--
--	registerMailbox({mailboxRegistrant}, ...)
--
--		Registers a mailbox which will drop messages into a 
--		mailbox matching id, if acceptTest(message) returns true. 
--
--		See the mailboxRegistrant definition for more details
--		
--	Returns:
--		true if successful
--		false if unable to register
--]]