Fixed shoddy packet typing
Added basic hearbeat framework
Client-side heartbeat is working
UDPNetworkUtility accepts addresses by value, encapsulated ClientData

I started encapsulating ClientData, and I added the internals for the
heartbeat ssytem. However, when I took a look inside UDPNetworkUtility, I
realized that I didn't have to pass the IPaddresses by reference anymore.
Therefore, I've changed it to accept the addresses by value, and I'm
committing that change right away before I finish the heartbeat system.

This engine is really shaping up, I think.
The server-side heartbeat is working and stable
Merge branch 'develop', heartbeat systems