Template. Retrieves current statistics for the world [W, STATS] = WORLD_RESET(W, WHAT) Retrieves the current custom statistics maintained by the world Parameters: ARM - the world WHAT - what kind of statistics to return: 'trial' - return trial statistics 'synthetic' - return synthetic statistics at the end of learning. Returns: W - the possibly altered world STATS - the statistics structure. Anything the world implementation considers necessary to store. See also world, world_dynamics