Investigate possibility of splitting .net assemblies

[jumpinjackie]

Although the original intent was to keep a monolithic assembly, it does complicate things if we want to introduce mg-desktop (that builds on top of the same common core) into the mix, which hampers our re-usability story which would be restricted down to source-compatibility.

So despite the initial rejection of preserving the split-assembly idea, we should at least try to see if it is possible at a minimum to split off the (Foundation, Geometry, PlatformBase) parts of the MapGuide API and have the (MapGuideCommon, WebSupport, WebApp) part depend on it in another assembly.