Refactor evaluation code a bit (prepare for model loading capability)
Evaluate: raise translation threshold
Add directory for saved models
Shuffle data set before training / testing
Save trained models
Fix evaluator multiprocessing
Fix model save
Neural model fixes
Evaluate: save trained model before evaluating
Neural network translation model fixes
Tweak NN parameters
Start "tools" directory
build_vsm: refactor to support multiple corpus types; add Wikipedia
corpus support
Add custom WikiSentenceCorpus class for generating sentences from
Wikipedia dump
build_vsm: adapt for new WikiSentenceCorpus