As documented at:
https://msdn.microsoft.com/VBA/Excel-VBA/articles/borders-tintandshade-property-excel

A stub for now.

Change-Id: Id422f3585ced7df59112f6757aeef0860bb0210e
Reviewed-on: https://gerrit.libreoffice.org/39381Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tamás Bunth <btomi96@gmail.com>