[Nautilus-list] Handling .desktop and .link files better.

[Jonathan Blandford <jrb redhat com>]

Currently, nautilus can't handle dragging nautilus link files or
.desktop files to the location bar.  While this is pretty easy to
special case in:
nautilus/src/nautilus-location-bar.c:drag_data_received_callback,
it leaves a slight bad taste in my mouth.  Is there a better place to
handle these?

Thanks,
-Jonathan