highgui_xaml project: added video.cpp/.hpp, added opencv refs
main.cpp: enabled image processing code in cvMain()
package manifest: enabled webcam cap
video.cpp/.h: new files added which contain all MF functionality (added to app project)
MainPage.xaml.cpp/.h: removed MF functions from the ref class, added HighguiBridge_OPEN_CAMERA processing on UI thread
cap_winrt_highgui.cpp/hpp: added input and output swap buffers, code cleanup
cap_winrt.cpp/.hpp: updated grabFrame and retrieveFrame code to handle device start with index, width, height sent to video class from output Mat