Remove useless this pointer.
Add a constructor to Event that does not require an ID.
Merge pull request #2 from Neki/topic/bf_network

Implement the basic network API structure.
Add a GameTimer class to provide reference timestamps during a game.
Add sending and receiving ping_packets.
Check protocol and version of received datagrams.
Add some logging.
Fix confusion between packet ID and packet type.
Log received packet ID.