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
- Made use imread() in OcvImageProcessing sample.
- Added test/sample logic to verify file creation via imgcodecs.
Signed-off-by: Maxim Kostin <v-maxkos@microsoft.com>