Intro nb added
clean up and regression
preprocessor example
Regression nb
lars section
some more additions
revamp structure
refine lars and intro
loss functions added for Gradient Boosting
some cleanups
more cleanups
handled special case in anova_f_test, CHAID notebook added
Modified argmax() method of
    * MultilabelModel
    * HashedMultilabelModel
to give correct value of ret->score
fixed defects found by Coverity Scan
update the LogitVGPiecewiseBoundLikelihood class
decision tree notebook updated
Update LibLinearRegression.h

make doxygen produce a link to enum
Update OnlineLibLinear.h

make doxygen produce a link to enum
Loss functions : minor changes and unittests
CLDA unittest added