Update to the latest CometD code.

This still won't work on anyone else's machine unless you clone https://github.com/SamirTalwar/cometd and `mvn install` it first.
Listen on the external host name as well as "localhost".
Log publish and subscribe commands for debugging purposes.
A tic-tac-toe board. No game logic yet.
Extract common behaviour from the director.
Detect a draw and stop the game.
Stop players clobbering each other.
Strikes!
Prepare for Heroku deployment.
CometD now works with Faye!