Using validate-model

Part of Henry's new perceptron stuff is 'validate-model', which TODO TODO TODO has something to do with validation of a model.

Henry says: 'you set your options in config and then run validate-model to compare two runs, ./compare-models foo/validate foo2/validate'. He also says: 'it's what you do before you do your final score generation'

I'm actually just putting this page here in the hopes that somebody who knows about this stuff will bother documenting it.