This allows to avoid the "(Visual Studio 2015)" labels next to project
names in Solution Explorer; and also avoid multiple warnilgs like

    project-name.vcxproj : warning  : The build tools for Visual Studio
    2015 (v140) cannot be found. Install Visual Studio 2015 (v140) to
    build using the Visual Studio 2015 (v140) build tools.

in IDE's Output pane in case VS2015 is absent locally.

Change-Id: I53b68ac810cbf2a31667c35dd549310e7209e010
Reviewed-on: https://gerrit.libreoffice.org/59797Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
Tested-by: Mike Kaganski <mike.kaganski@collabora.com>