Added support for Brownboost, Logistboost as well as Stump regression…

… and Stump classification algorithms to daal4py.

Added support for Adaboost classification algorithm, including support for method=SAMME or SAMMER for multi-class data.
Variable Importance feature has been added in Gradient Boosting Trees.
Ability to compute class prediction probabilities has been added to appropriate classifiers, including logistic regression, tree-based classifiers, etc.

Merge pull request uxlfoundation#135 from IntelPython/fix-k-means-n-i…

…nit-on-given-initial-array

KMeans sklearn API class change

Merge pull request uxlfoundation#128 from IntelPython/fix-tests-again…

…st-master

Fix tests against master

Merge pull request uxlfoundation#101 from IntelPython/bump-sklearn-ve…

…rsion

Bump sklearn version

Merge pull request uxlfoundation#48 from IntelPython/feature/print-be…

…havior

Feature/print behavior

Merge pull request uxlfoundation#36 from SAT/feature/nocopy

disallow algorithm copy-construction and assignment, Avoid constant c…