Add WiX Builds into VisualStudio/MsBuild

We need to take the stuff which is currently scattered inside two batch files and a wix include file and put them into proper projects within the Shibboleth master solution (.sln). Then we can arrange to collect parameterization from the MSBuild properties file and get the dependencies such that you just say "build" and out pops all the msm and msi files that you need.

This was not done in the first pass of Wix-isation so as to control risk, but it leaves the Windows build needlessly fragmented, tedious and this risk-prone.

Wix has support for most of this stuff so it is "just" a matter of swapping in the tech and building the thing.