Change SVM to use {0,1} labels.
Also add a data validation check to make sure classification labels
are always 0 or 1 and add an appropriate test case.
Fix SVM model and unit test to work with {0,1}.
Also rename validateFuncs to validators.
Specify label format in LogisticRegression.
Add an option to turn off data validation, test it.
Also moves addIntercept to have default true to make it similar
to validateData option
Merge pull request #819 from shivaram/sgd-cleanup

Change SVM to use {0,1} labels