Rename the install projects to clutter-install so that it would be easier
to use the project file set as a part of a grand solution file, such as
one that is used to build the entire Clutter stack.
...and drop these project files, as the way how the conformance
tests are built has been totally reworked. Instead, in the future,
use NMake Makefiles to build them, which will be proposed later.
-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
-Add configuration in Clutter projects to add option to build Clutter with
the GDK3 backend in addition to the Win32 backend
-Add another preconfigured clutter-config.h.win32_GDK which contains
backend configs for both GDK3 and Win32 windowing and input.
