Renamed apply_multiclass_multiple_output to apply_multilabel_output
Renamed python example classifier_multiclassmultipleoutputlinlinear_modular.py
Merge pull request #2096 from Jiaolong/refactor_MulticlassMultipleOutputLabels

Renamed apply_multiclass_multiple_output - Thanks for fixing!
Added multilabel reader in LibSVMFile.
Added multilabel writer in LibSVMFile. Updated LibSVMFile unit test.
Corrected indent issues and memory leak.