#237 JBossMQ now disconects clients with stale connections.

[Hiram Chirino]

Sometimes clients disconnect from the server but the
server does not notice (This is especialy the case with
stateless protocols like RMI). Added an interceptor to
the DestinationManager that keeps track of when the
client last accessed the server. If the client is idle for
too long, the client gets disconnected.