added perf test for CalcBackProj
Merge branch 'master' of https://github.com/Itseez/opencv into back_proj_fix
FEATURES2D: add DenseFeatureDetector Python wrapper
UMat map-unmap synchronization test
changed type of sanity check
added jpeg progressive support.
Fixed stereoBM for Intel CPU.
Merge pull request #2378 from ngryman:progressive_jpeg
Merge pull request #2478 from clemenscorny:master
improved cv::filter2D
Merge pull request #2528 from mlyashko:back_proj_fix
Merge pull request #2529 from ilya-lavrenov:tapi_filter2D
Merge pull request #2505 from alalek:umat_unmap_synchronization_test
UMat: issue in OpenCLAllocator::unmap()
disable failed tests
Merge pull request #2286 from alalek:umat_unmap_issue
Fixed incorrect calculation of best_disp
Merge pull request #2535 from akarsakov:stereobm_fix
added test by picture
Merge branch 'master' of https://github.com/Itseez/opencv into back_proj_fix1