Patch for missing @Gtk::Gdk::PixbufLoader::ISA

[Christian Borup <borup borup com>]

Hi there

I was playing around with the PixbufLoader but much to my surprise I
couldn't connect signals to the PixLoader object because the @ISA was
not set.
Attached is a patch that fixes that and generally cleans up
GdkPixbuf.pm.

Is this the right way to fix it?

./borup