applying patch by rxtsolar: https://github.com/Itseez/opencv/pull/5422 for the master branch (even though it's actually not that important here)

1) fix multichannel support
2) remove useless bad_value, read value from original Mat directly
3) add more tests
4) fix docs for cvCeil and checkRange

WinRT parallels library is causing conflicts in VC++ due to inconsistent usage with C++/CX which is now present in parallels.cpp.  This support should be included in all projects with WinRT specific code except if doing special native C++ tasks.

Fix C++/CX support for all WINRT and bring back native-mode only support which was removed

so it matches the code.