Fixing bugs where unseeded random numbers in mappers can result in failures.
Adding a category to number transformer as a utility program.
Properly handling empty column values.
Using the broadcast variable to send out value mapping.
Adding a category feature coarsener.
Fixing a coarsener bug.
Adding map saving for the coarsener.
Handling new category values as missing values when transforming a test data set.
Handling new category values when transforming.
Adding an imputation technique for both training and predictions. Categorical features are now split in a binary fashion. A lot of refactoring and cleaning up.
Adding a few fixes for prediction and validation routines.
Adding fixes for log loss computations.
Adding more efficient sorting for categorical feature splitting.
Additional fixes after merging with the master branch bug fix.