[ewlqabvk] Random mixture of computer opponents

The goal is to create a "standard" chess opponent to control rating inflation in humans.

Select a set of varied computer engines.  Adjust amount of time each engine gets so they are about equal when they play each other.  Then synthesize a virtual engine which picks a random engine for each move.  Play this mixture engine against the pure engines.  Calibrate again if necessary.  Check to make sure one program isn't making all the losing moves.