of WINRT samples

This removes requirement to add OPENCV_WINRT_INSTALL_DIR with backslash in the end

in case trailing slash is presented VS handles duplicated slashes w/o issues

clip the found objects in HOG as well (http://code.opencv.org/issues/3825); added test to check CascadeClassifier on small images (http://code.opencv.org/issues/3710)

improvements in Haar CascadeClassifier: 1) use CV_32S instead of CV_32F for the integral of squares (which is more accurate and more efficient); 2) skip the window if its contrast is too low

Signed-off-by: Maxim Kostin <v-maxkos@microsoft.com>

Signed-off-by: Maxim Kostin <v-maxkos@microsoft.com>

code changes to handle the failed build

Conflicts:
	modules/highgui/src/cap_ximea.cpp

Conflicts:
	modules/highgui/doc/reading_and_writing_images_and_video.rst
	modules/highgui/src/cap_dc1394_v2.cpp

Conflicts:
	modules/highgui/include/opencv2/highgui/highgui_c.h
	modules/highgui/src/cap_dc1394_v2.cpp

fix typo

Conflicts:
	modules/objdetect/src/hog.cpp

fix android build