[libvirt] [PATCH 2/2] Java bindings for domain events

This patch allows the remote driver to work with an asynchronous EventImpl (it's the only one using an externally-supplied one), assuming libvirt is compiled with pthread support. (Without pthreads, this code is harmless in a single-threaded environment.) Basically it uses a mutex to protect reads from the RPC socket in such a way that message reads (in their entirety) are done atomically (otherwise the remoteDomainEventFired() can race the call() code that reads replies & events). In addition, I update the EventImpl handle to prevent remoteDomainEventFired() from being called everytime a reply is sent. (This helps us dispatch events in a timely manner, though it's not strictly necessary. Without it, any events coming in during a call() won't be dispatched until the call drops the socket lock (because remoteDomainEventFired() will be stuck awaiting the lock). Dave