Merge pull request #57 from cowboy129/master

Avoid disconnect cycle
Disable websocket compressing by default.
oops.
Used PoisonPill to stop SocketIOServerConnection actor to make sure the
messages of Disconnect etc. could be sent. This should also fixed memory
leak.
=ben Adjusted cluster heartbeat configurations.
Don't make tranportConn = null during on DisconnectPacket.
Upgraded to akka-2.3.3
set cluster.scheduler.tick-duration=9ms to force cluster use a dedicated
scheduler; makes the cluster failure detector slightly more tolerant to
variations in heartbeat inter-arrival times.
Fine tuning for cluster dispatcher and netty worker pool.
Use quick recover setttings for cluster fail-over testing.
Let ConnectionActive to handle socketio heartbeat. Do not monitor
serverConnection anymore.
Renamed SocketIO*Connection to SocketIO*Worker.
Fixed case of closetimeout never take effect.
Used some empty value instead of null.
Fixed: ConnectionActiveStateSerializer should have unity identifier.
cleanup
Upgraded to akka-2.3.4. Bumped version to 0.1.3-SNAPSHOT.
Add UT to avoid duplicate serializer identifier