move core AM functionality to separate project

[garfieldnate]

The project could be much healthier if the core logic were in a separate repo, with this project simply being a bridge between Weka and that project. This would allow us to use the classifier in other projects without including all of Weka, plus having weka tightly integrated has brought a few maintenance issues:

• We're stuck on JUnit 3
• We have to catch generic Exception objects everywhere
• Instance implementations don't implement toString, equals, hashCode, or Comparable