It turns out that VS IDE's "Peek definition" (and other functions that
navigate to sources) fail if the short ("DOS") path to the file is given
in project's includes: see issue at
https://developercommunity.visualstudio.com/content/problem/139659/vc-peek-definition-fails-to-navigate-to-windows-ki.html

This patch converts the include paths to full Windows paths, to avoid the
problem. Also, since IDE starts working correctly with this change, this
patch removes inclusion of "inherited" paths "$(IncludePath)", which are
the paths added by Visual Studio itself. Since we do specify all include
paths explicitly, that is not required, and avoids confusion.

Change-Id: Ide2d948f8c7b050b02f550342144fede4fcafb82
Reviewed-on: https://gerrit.libreoffice.org/53731Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>