Random Forest (Leo Breiman)
+ Add random forest classifier in ML/Classify.ecl
+ Add supporting functions in ML/Trees.ecl
+ Add supporting functions in ML/Sampling.ecl
+ Add example file supporting ML/Test/Explanatory/RandomForest.ecl
Changes based on Pull Request comments.
Clean comments
Restructure Regression to use folders.  Make dense Beta function match Sparse

Signed-off-by: johnholt <john.d.holt@lexisnexis.com>
Merge pull request #145 from DonVitorio/RandomForest

Random Forest Classifier (Leo Breiman's algorithm)
Merge pull request #154 from johnholt/regression_modules

Restructure Regression to use folders.  Make dense Beta function match S...