Connection factories and connectors

[timfox]

As per http://jira.jboss.com/jira/browse/JBMESSAGING-294 connection factories now specify the remoting connector they wish to use.

So we can simultaneously have multiple connection factories using different transports on the server.

[ovidiu.feodorov]

* Tests
* Documentation

[timfox]

tests already there
need to update the documentation