* Changed the way the QueueEmpty callback is fired. It will be fired asynchronously as soon as an empty queue is detected (this can happen immediately following a dequeue), and will not be fired again until at least one packet is dequeued from that queue. This will give callbacks advanced notice of an empty queue and prevent callbacks from stacking up while the queue is empty
* Added LLUDPClient.IsConnected checks in several places to prevent unwanted network activity after a client disconnects
* Prevent LLClientView.Close() from being called twice every disconnect
* Removed the packet resend limit and improved the client timeout check
* Clients are no longer disconnected when a packet handler crashes. We'll see how this works out in practice
* Added documentation and cleanup, getting ready for the first public push
* Deleted an old LLUDP file
* Replaced logic in ThreadTracker with a call to System.Diagnostics that does the same thing
* Added Util.StringToBytes256() and Util.StringToBytes1024() to clamp output at byte[256] and byte[1024], respectively
* Fixed formatting for a MySQLAssetData error logging line
