changes to gtk

Hello crux users! I've included support for gobject-introspection to gtk and related ports. The ports touched by this are as follows: gdk-pixbuf pango atk gtk gdk-pixbuf now lists gobject-introspection as a dependency but will still build without it. It will however result in a footprint missmatch for all ports listed above. To include gobject-introspection support in gtk, you will need to rebuild pango, atk and gtk after installing gobject-introspection. Sorry for any inconveniences this may cause. -- Fredrik Rinnestam