Add GenProg-default coverage/localization behavior.

[clegoues]

Sometimes called "weighted path" --- check which statements are executed by failing test cases, give a weight to statements not also executed by a passing test case, and some other weight by those that are. Weight of 0 to statements not executed by failing test case.

Those weights are configurable in GenProg. Defaults are 1.0 for failing only and 0.1 for failing + passing, even though those weights are bad. shruggie emoji