Eliminate JNP usage in HornetQ

Currently HQ is using JNP to get the JNDI mapping for queues and stuff. This will be changed to use a client-side JNDI URL scheme, such as "hq:xxxx" to generate the client-side interfaces much like EJB uses the "ejb:" scheme. There is no server-round trip for this and it will enable us to remove the JNP sockets from the server configuration, which should never have been introduced.