MAHOUT-1541

Not ready for merge, just looking for a checkpoint review. The code works and I'm reasonable happy with it. It needs review for:
* Design: will it be flexible, are there better ways to organize the code?
* Scala usage: I'm pretty new to Scala. 
* Package structure: no clue here so its all in "drivers"

Please don't take the tests too seriously and some things are not implemented. I'd like a once over before I do a bunch of test cases and finish polishing up.

This will close three tickets when complete. MAHOUT-1541, MAHOUT-1568, and MAHOUT-1569

Docs written describing this here: https://github.com/pferrel/harness/wiki
Hm. i'd still rather delegate than extend, 

Then you can either expose parameters as a public value; or, assuming you just want to be able to write schema.any-MapLike-method, you can provide an explicit conversion from Schema to MapLike.