Implemented a spectator mode that appears to function properly.  Right
now, for testing purposes, it is set up so that every game has 1
spectator in addition to the specified number of players.  Hence, a
4-player game will need 5 clients connect in order to begin, with the
last client being the spectator.

TO DO:
*Specify number of spectators via command-line argument.  Absence of
such argument will default to 0 spectators.
*Allow number of spectators to be specified in GUI host options and
Metaserver server spawn options.