Solo refactoring

I did most of the changes requested in our master pull request. The only ones I didn't address were changing the class of FitnessValuePair to a .java class (which is untenable, but we may be able to make it immutable? I didn't find a good way to do that), and renaming ParentChildEvolution to Mu,LambdaEvolution or MuCommaLambdaEvolution. I think we should probably do the last one, but I didn't want to make this pull messier than it is without you getting a chance to look at it.