Game playing works reasonably well now.  Need a way to handle IGS challeges.  Also need to make the messages support IGS.
* gochannel.d: Fixed multiple issues in GoChannel. Need to add
  support for undo, pass, resign, and scoring.

* connectionset.d: Allow ConnectionSet's to be "quit" so we can boot
  off all the users in a set.

* core.d: Fixed destroying connection objects after unsubscribing
  users was added to the Channel class. :/

* igsconnection.d: Fixed multiple issues, and added some additional
  commands.

* package.d: Added igscodes to default import to ease supporting IGS
  in the various messages.

* wsconnection.d: Fixed quitting via a command.

* goban.d: Added an example of how to print the goban. Not implemented
  yet.

* chat.d: Fixed IGS support of chat messages to use the new IGS codes
  enum.

* game.d: Added more support for IGS and a few more game messages.
  Need to add proper handling of game messages and challenges.

* gametree.d: Fixed game tree toSgf's default depth to be max.

* igscodes.d: IGS codes from NNGS. Now we know what those damn numbers
  should be.