-Combine entries in the property sheets and make it a bit more flexible,
and drop some redundant items
-Use Custom Build Rules for generating enumeration and marshalling sources,
and the .def file so that they can be wiped off when a "clean" is
requested, and regenerate automatically when the templates/.symbols
files are updated.
-Improve consistency by using ApiVersion rather than ClutterApiVersion
with the Visual Studio project for other components of the Clutter/GTK+
stack
-Get rid of unneeded configs in the "install" project
Apparently the update to build the GDK backend broke the "installation"
process of the binaries. Fix that by grouping the binaries as Release or
Debug.
