Implemented MDB Container

[Dain Sundstrom]

I checked in an implementation of a MDB container for OpenEJB 3.  Is  
is based on the container in OpenEJB 2, but is otherwise completely  
untested.  It is wired into deployment, so if you deploy an  
application with a MDB it should be hooked up to ActiveMQ.

Does someone want to work on itests for Message Driven Beans?  Please :)
-dain