code: def parseOneGame(self):
  		
  		if self.index < self.datalen:
  			match = self.reGameTreeStart.match(self.data, self.index)
  			if match:
  				self.index = match.end()
  				return self.parseGameTree()
  		return None
docs: Parses one game from 'self.data'. Returns a 'GameTree' containing
  			one game, or 'None' if the end of 'self.data' has been reached.