Entropy Minimization Discretizer

Recently we have commented with Ameet Talwalkar the possibilty of including both Feature Selection and Discretization algorithms to MLlib.

In this commit we have implemented the Entropy Minimization Discretizer based on the paper
[Fayyad and Irani, Multi-Interval Discretization of Continuous-Valued Attributes, 1993]. This is one of the most used Discretizers which is included in most libraries like Weka, etc. This can be used as base for FS algorims and the NaiveBayes already included in MLlib.