Fixed pregame starting game with empty teams

Also added an option to cancel the starting countdown if a commander
leaves the chair/hive.
Fixed the old timer based pregame

This now also doesn't start on empty teams.
Notify on empty

Tell the players the countdown was cancelled.
Really fixed the old timer based pregame

Would help if I checked for empty teams before letting it say "Game
starts in blah"...
Ensure countdown text is removed

If we're cancelling the game start.
Merge pull request #44 from Person8880/develop

Pregame fixes and improvements