Issue #2540 : Python bindings for various "detectMultiScale()"
Added Haar cascade for russian cars licence plate detection, 16 stages cascade, pretty fast.
Fixed pyopencv_to w/FLANN IndexParams in python3.

The keys() and values() functions on dictionaries in Python 3 no longer
return lists.  pyopencv_to() for flann::IndexParams now iterates over
the dictionary in a way that is version-agnostic.
OCL: matchTemplate: changed perf test
opencl opticaflow fix that enables buffer2image extension
Merge pull request #2797 from ElenaGvozdeva:ocl_MT
perftest for floodfill
Merge pull request #2782 from HapeMask:py3_flann
Merge pull request #2777 from alexstadnik:master
Merge pull request #2773 from abidrahmank:pycascade
added missed tests for cv::norm, cv::normalize
Merge pull request #2804 from ilya-lavrenov:tapi_perf
Merge pull request #2638 from mlyashko:floodfill_perftest
fix according review
Merge pull request #2800 from krodyush:pullreq/140516-opticalflow-imgext-fix