Add early termination to ensemble model training.
Including algorithm to make codes compilable at Ubuntu
Merge branch 'jfeng-mozsci-01' of github.com:seomoz/mozsci into jfeng-mozsci-1
make it compilable under Ubuntu. Merge two branches.
Merge pull request #2 from seomoz/jfeng-mozsci-1

Add early termination to ensemble model training and serialization/deserialization