Adding support for WinRT(WinPhone 8/8.1 and Win Store) via CMake 3.1

- Substituted HAVE_WINRT with WINRT
- Fixed compilation issues in ocl.cpp and parallel.cpp
- Fixed compiler issue for WP8: "C2678: binary '+' : no operator found which takes a left-hand - Fixed gitignore
- Added #ifdef HAVE_OPENCL to remove compiler warnings in ocl.cpp
- Used NO_GETENV similar to '3rdparty\libjpeg\jmemmgr.c;
- Added ole32.lib for core module (for WindowsStore 8.0 builds)
- Made OpenCV_ARCH aware of ARM

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

.gitignore

@@ -8,3 +8,12 @@
 Thumbs.db
 tags
 tegra/
+bin/
+CMakeFiles/
+*.sdf
+*.opensdf
+*.obj
+*.stamp
+*.depend
+*.rule
+*.tmp