Intro nb added
clean up and regression
preprocessor example
Regression nb
lars section
some more additions
revamp structure
refine lars and intro
Modular API for RF and minor fixes
loss functions added for Gradient Boosting
some cleanups
minor change in Random Forest
more cleanups
added graph cut and unit-test
Merge pull request #2319 from Jiaolong/graph_cut

added graph cut and unit-test
Merge pull request #2311 from mazumdarparijat/rf

Modular API for RF and minor fixes
fixed defects found by Coverity Scan
update the LogitVGPiecewiseBoundLikelihood class
Merge pull request #2329 from yorkerlin/develop

update the LogitVGPiecewiseBoundLikelihood class
Merge pull request #2324 from mazumdarparijat/documentation

handled special case in anova_f_test, CHAID notebook added