Install the Python scripts that is used by gdbus-codegen in
share\glib-2.0\codegen, to be consistent with the other platforms.
Please see https://bugzilla.gnome.org/show_bug.cgi?id=702862 for details
on this.
Like the Visual Studio 2008 project files, split up the property sheets
so to ease maintenace, and to prepare to use autotools to fill in the
header entries to "install".
Put some of the items that are frequently repeated in the projects as well,
also to simplify maintenance.
Also, update the autotools files to automate the upgrade of Visual Studio
2010 project as we now have multiple property sheets to copy and process.
