Added clamp() for THRESH_TRUNC mode
optimized stitching warpers
A more efficient workaround for erode
Optimized memory access by using stride pattern
T-API: optimized ocl_flip
Remove a useless loop that copies an array to itself
Merge pull request #2768 from SpecLad:useless-loop
Fixed several problems found by PVS-Studio.

This fixes all problems from the article "Checking OpenCV with PVS-Studio"
<http://www.viva64.com/en/b/0191/> that are not already fixed and are
not in 3rdparty or the legacy module.

The problems fixed are two instances of useless code and one instance
of unspecified behavior (right-shifting a negative number).
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.
Added more info on the data input variable of kmeans
Merge pull request #2742 from StevenPuttemans:feature_3176
icv: enable public IPPICV packages
optimized cv::repeat
icv: fix test eps on Mac for failed perf test
Merge remote-tracking branch 'origin/2.4' into merge-2.4
run.py: added --android_env parameter
run.py: propagate OPENCV* env variables only with --android_propagate_opencv_env flag
Optimize openCL version of reduce function