cap.cpp: switched to single buffer mode for input
cap_winrt_highgui: added HighguiBridge::createTrackbar
cap_winrt_video.cpp: enabled flipping and swizzling code
window.cpp: implemented cvCreateTrackbar2 using XAML slider
MainPage.xaml: added <Slider Name="cvSlider" ...
MainPage.xaml.cpp: impl XAML elements and HighGuiAssist_SHOW_TRACKBAR UI thread event
MainPage.xaml.h: note: how to add callback for slider value change?
added code for createTrackbar() and not to reprocess the same frame again