added packet library 'launch'
added launch to client and server reqs
if client doesn't hear from server for 10s assumes connection lost
added heartbeat periodic callback to server (that only logs currently)
packet header data being packed
added common/protocol for both client and server to share
* server now removes disconnected client connections
* sending heartbeat packet to all connected clients
set client ConnectionReader.setRawMode(True) to take care of
ConnectionReader.dataAvailable blocking
implemented __str__ in launch.Packet for py2