Here's a patch for 3B21c, that adds autokick function, if there are no human players playing the game (dead or alive, not counting spectators). I've also rewritten some small pieces of code in StartFrame: combined some lines that depended on the same coditions, removed g_iNum_hum_tm and g_iNum_hum_tm_prev (use g_iNum_humans instead, it's the same thing, and we still check g_i_cv_BotsQuotaMatch when we use it to compute g_iPeoBotsKept). I've also rewritten the autokill function, there's no need to copy&paste existing code.
It seems I can't attached it here, get it here:
http://www.sendspace.com/file/csj3op