Added cPlayer::GetEffectiveGameMode().
Added cEntity:GetYaw() and cEntity:SetYaw().

This is the preferred way to get / set rotation, GetRotation() and SetRotation is obsoleted due to bad name.
ProtoProxy: Fixed handling of incomplete packets.
ProtoProxy: Removed unused enums.
ProtoProxy: Fixed the SpawnObjectVehicle packet.
ClientHandle: Fixed an error in player-joining hook.

Players being disconnected used to fire the PlayerJoined hook repeatedly.
cByteBuffer: Fixed GetUsedSpace() off-by-one error.
Protocol 1.7: Rewritten packet-sending to use cPacketizer.

Implemented enough of the protocol that the client now spawns in the world (but cannot do anything).