Add a new variant of detectMultiScale with output arguments 'objects' and 'numDetections'; factor most of detectMultiScale's code into 2 protected methods
Merge pull request #976 from PeterMinin:num_detections
Merge pull request #990 from asmorkalov:pthread_build_fix
little refactoring
--amend
Merge pull request #983 from HapeMask:python3-compatibility
Merge pull request #1003 from vhdirk:gstreamerfixes
Merge pull request #978 from jet47:gpuarithm-refactoring
Merge pull request #977 from jet47:gpucodec-refactoring
refactored box filter
refactored Linear Filter
refactored Laplacian filter
refactored Separable Linear Filters
refactored Morphology Filters
refactored Image Rank Filters
refactored 1D Sum Filters
refactored StereoBM
refactored StereoBeliefPropagation
refactored StereoConstantSpaceBP
refactored DisparityBilateralFilter