Unit tests in MOA

Today, I added a basic junit testing framework in MOA for classifiers. Though still based on the trusty old 3.8 branch, rather than 4.x, it will give the MOA dev team peace of mind when they’re completing their code migration to a refactored and generalized architecture, away from weka.core.Instance. One major reason for sticking with 3.8 was to simply re-use a lot of code that I developed for ADAMS over the years. This made it very fast to set up the testing rig for MOA.