[CMake] VS2017 + CMake integration

[Robert Dailey]

First of all, I personally find the CMake integration in Visual Studio
just absolutely amazing. Granted I am not doing any cross-compiling
with Android yet, but for just building on Windows it's phenomenal.

I noticed that Visual Studio 2017 RC is actually packaging its own
version of CMake:

E:\PROGRAM FILES (X86)\MICROSOFT VISUAL
STUDIO\2017\PROFESSIONAL\COMMON7\IDE\COMMONEXTENSIONS\MICROSOFT\CMAKE\CMake\bin\cmake.exe

Is Microsoft patching the CMake code base to support what they are
doing? And if so, are those changes not upstream yet? Personally, I'd
rather have the ability to tell Visual Studio to use my external
version of CMake that is on PATH, rather than its own. I can
understand if that isn't possible right now due to custom changes, but
I'm curious to learn more, assuming Kitware has had a partnership with
Microsoft for this integration with Visual Studio.

Would anyone be able to provide more news here? Is there a way to make
VS 2017 use my separate install of CMake? Are the Microsoft-specific
patches contributed to upstream (or planned to be)?