Genericize for any usage: * adapt it to other (non-boardgame) workloads * Break the players=2 assumption * Get the necessary metadata into the Physics plugins, to allow the tournament system to figure out how many critters to put into each match. * Handle the n=1 case * Handle the n>2 case * Break the direct-competition assumption * Physics->double_match should become an internal method; it shouldn't be called directly. * Maybe Physics plugins should implement a specific ->fight() More Physics plugins: * Go * OCR * Speech recognition * Weather prediction Portability: * I know it works on linux * I doubt it works anywhere else. (patches and test reports welcome) Other issues: * Disable migration by default. * Figure out why L::B hangs sometimes, and fix that.