added constructors for LogDetEstimator
added tree structures for id3
initial commit of train_multiclass_svm. Issue #1868
revert the changes of 56ceab6 for main_unittest.cc
better indentation and better logging
more refactor and decoupling
decoupling CLI from training. train_multiclass can be reused in the future
added new license
added benchmarking for training
Solve memory leak problem, but uninitial values jump problems didn't fixed. I need help~
added closing statement
remove useless function
Adding MultilabelLabels as a new output type.  Plus unit-tests.
added constructors LogDetEstimator,unit tests for those and added get methods for private variables of LogDetEstimator
remove unwanted SG_SDEBUG messages from unit-test
add streaming mmd, refactor linear time mmd
fix doc error
BinaryTreeMachineNode created
Merge pull request #1960 from lambday/develop

remove unwanted SG_SDEBUG messages from unit-test
fixed typos in #1940