Add "survival" option in "/gm" command

BauSystem_Main/src/de/steamwar/bausystem/commands/CommandGamemode.java

@@ -66,6 +66,8 @@ public class CommandGamemode extends BukkitCommand {
 				return GameMode.ADVENTURE;
 			else if ((modeArg.equalsIgnoreCase("spectator")) || (modeArg.equalsIgnoreCase("sp")))
 				return GameMode.SPECTATOR;
+			else if ((modeArg.equalsIgnoreCase("survival")) || (modeArg.equalsIgnoreCase("s")))
+				return GameMode.SURVIVAL;
 		}
 		return null;
 	}