This updates the property sheets that are used to "install" builds of GTK+
after the libraries and the gtk3-demo programs are built. Note that these
are generated with scripts in regards to the headers part, so that we can
move the header installation part to use autocompletion by the autotools
build files in the next dev cycle or so, like the "gdk" and "gtk" project
files.
a14c7cbfa1