Adding MultilabelLabels as a new output type.  Plus unit-tests.
Fixing indentatino with "bcpp".
Changed license to BSD.
Replaced mclass_t by int16_t.  init() is first call in every constructor.
Small indentation fixes.
Removed TODO.
Changed license of unit test and fixed indentation with astyle.
Removed duplicate "const" specifiers.
Changing mclass_t to int16_t in unit-test.
Formatting of unit test: Use tabs instead of spaces.
Moving STL includes to save()/load() methods, so we'll remove then together with load()/save().
Multilabel: changed init() to init(num_classes, num_labels)
Changing formatting, printf and asserts to something more sho-goon-ish.
Fix clone unit test and clone method (by calling SG_ADD in init()).
More verbose error messages.
Changing visibility of variables.
Changing indentation of Multilabel files to latest style.
MultilabelLabels: Marking work-in-progress parts of init(). -- Issue #1972
MultilabelLabels: Removed save()/load() from labels class - will be moved inside some IO class.
Merge pull request #1958 from tklein23/labels_classes_for_multilabel_learning

Output classes for Multilabel learning.