Fix failure of KNN with cross-validation and memory leak on Features copy constructor.
fixed defects in graph cuts
changes for peer review
remove the eigen3 header files
Merge pull request #2453 from Jiaolong/fix_defects

fixed defects in graph cuts
Scene classification notebook added
notebook polished
added check for opencv version
peer review changes
Merge pull request #2500 from yorkerlin/develop

remove the eigen3 in header files
Merge pull request #2430 from kislayabhi/scene

Scene classification notebook added
Merge pull request #2491 from Jiaolong/graphcuts_peer_review

changes for GSoC peer review
Small changes in LMNN notebook to reduce running time.
Merge pull request #2499 from khalednasr/neuralnets_cpp_examples

added cpp examples for neuralnets
Merge pull request #2501 from iglesias/notebook/lmnn

Small changes in LMNN notebook to reduce running time.
Update InferenceMethod.h

Fix wrong statement in documentation
Update InferenceMethod.h

another fix, overseen before
Merge pull request #2496 from iglesias/fix/knn_with_cv

Fix failure of KNN with cross-validation and memory leak on Features copy constructor.
fixed #2502