implemented extraction of tf-idf features, not tested
Merge branch 'hank' of https://github.com/bolei/miRNA-active-learning into bolei
tfidf feature extractor tested, fixed some bugs, good to use
Merge pull request #1 from bolei/hank

Hank
Merge pull request #2 from bolei/hank

Changed featuresFile to formattedDataFile
Merge pull request #3 from bolei/bolei

Bolei
Changed features file