Update google-collections to guava

[Loki-Afro]

Hey, I just found out that the watchmaker framework uses the google-collection library which is deprecated.

The new google library is called guava.

See here: http://code.google.com/p/google-collections/

[mikedanese]

Guava is supposedly fully compatible with google-collections and will include further bug fixes. Might be a useful bit of maintenance, I will look into how much of a process this will be.

[dwdyer]

Watchmaker only uses a single class from Google Collections, MapMaker in CachingFitnessEvaluator.java. It might be possible to eliminate the dependency entirely.