This commit fixes our longstanding build artifact output issues and
finally unifies all C++ project output into bin/ and obj/.
In light of that, I've removed NoOutputRedirection.
I've also updated WTU and U8U16Test to use our common build props and
fixed any warnings/compilation errors that popped out.
I validated this change by running repeated incremental builds after
changing individual .cpp files in many of our C++/WinRT projects.