Add Reference Collection logging to the WeakReferenceMessageHandle Class

To understand when the JVM purges our WeakReferences from memory we can add some debug logging that will print out when the References are collected by the GC: http://java.sun.com/javase/6/docs/api/java/lang/ref/ReferenceQueue.html

By providing a ReferenceQueue when we create a Reference then the GC will add the Reference to the Queue when it collects the referent.

We can then monitor the queue with a new thread on the blocking queue.remove() call.