Add overridable function to potentially allow games to start up even without any humans present if they wish. Defaults to NOT allow that behavior.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@4076 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/parlor/game/server/GameManager.java

@@ -677,7 +677,7 @@ public class GameManager extends PlaceManager
             }
         }
 
-        if (humansHere == 0) {
+        if ((humansHere == 0) && !startWithoutHumans()) {
             // if there are no human players in the game, just cancel it
             Log.info("Canceling no-show game [game=" + _gameobj.which() +
                      ", players=" + StringUtil.toString(_playerOids) + "].");
@@ -751,6 +751,15 @@ public class GameManager extends PlaceManager
         return true;
     }
 
+    /**
+     * @return true if we should start the game even without any humans.
+     *  Default implementation always returns false.
+     */
+    protected boolean startWithoutHumans ()
+    {
+        return false;
+    }
+
     /**
      * Called when the game is about to start, but before the game start
      * notification has been delivered to the players. Derived classes