Define Visual Studio cinder path in property sheet

Currently the cinder path for Visual Studio projects is hardcoded in 3 places: header search path, linker and resource settings. If instead a simple property sheet was provided in the template, then we could add a `CINDER_PATH` like we do with Xcode, and it would be much easier to update projects later. It would also give a nice place for users to add their own custom properties.
