resending, timeouts, packet discarding. Add notification event for
packet discarding. Add priority scheduling for packet queues.
Add outgoing duplicate detection facility. Correct packet sequencing.
Make provisions for automatic server side throttle adjustments (comes
in next installment)
* Added new generic "Location" class to handle 2D integer locations. Going to use it to replace all RegionHandle and X,Y coordinate references throughout the entire project. You have been warned.
* The BlockingQueue exposes Contains so we can make sure we don't add a TextureSender to the queue if there's already one present
* introduced some TryGetValue and various code convention stuff
