Merge branch 'TLD_Multi_Tracking_Support' of https://github.com/Auron-X/opencv_contrib into TLD_Multi_Tracking_Support

http://www.votchallenge.net/vot2015/dataset.html

1. Multi-tracker classes (multiTracker.cpp)
2. Multi-tracker example (multiTracker_test.cpp)
3. Fixed a rare bug (OpenCL runtime error)

http://www.votchallenge.net/vot2015/dataset.html

Adds example on segmented word recognition. Shows the use of the OCRHMMDecoder with the NM and CNN default classifiers.