we need to ref this object once we have a pointer to it or not.
By default this is set to true -- constructors and other functions
where we do own the object need to set this to false before setting
the "Raw" property. Also added Unref and RefCount methods.
* glue/object.c, glue/type.c: some utility functions for
refcounting support
* gdk/Pixbuf.custom: manually wrap a few functions so that
the refcount ends up being correct at the end (need an extra Unref)
* api/gdk-api.xml, sources/Gdk.metadata: metadata updates for
hiding manually-wrapped Pixbuf stuff
svn path=/trunk/gtk-sharp/; revision=8913
