Fix chan join tab complete bug
Wrap all game logic around the internal MC scoreboard

This has a few advantages, the main two being:

- Scores can be displayed using the scoreboard, not just the in chat.
- Future potential for players or plugins to interact with the
  game logic using standard commands or plugins.

The tests are restructured to run the game server and use real bukkit
instances of players and scoreboard objects. This is simpler than
mocking out all the scoreboard and server internals, and allows for
better integration testing.

Player channel data is restructured to give players individual settings.
Merge branch 'scoreboard'

Conflicts:
	src/main.py
Sort tab completion results
Update tab and help for scoreboard and setmy cmd
D'oh, add forgotten file for other commands
Fix game starting at same time as countdown
Add scoreboard command to show slot objectives
Use scoreboard teams to manage non-team players

- Not sure if there's a simple way to stop players appearing in the
  scoreboard player list, so for now all server players who are not in a
  channel game are kept in a dedicated team, and the team prefix is used
  to change the scoreboard colour to strikethrough their names, so it's
  easier to ignore them.

- Fixes broken non-team scoreboard displays.

- Fix bug in team assistance onPlayerDeath.
Replace 'helpme' command with 'usage'
0.1.5