Test for the CMake auto-setup package manager with a `vcpkg` setup.

Setting vcpkg is as easy as:

    git clone https://github.com/microsoft/vcpkg
    .\vcpkg\bootstrap-vcpkg.bat

Then you need to have `vcpkg` in the `PATH` environment variable.
(`PATH=${PATH};c:\projects\vcpkg` in Preferences -> Environment)
