* gdesktop.c: Moved the old DnD cruft to olddnd.c to keep it there
for reference purposes.
* gmetadata.c: Removed the gmeta_get_icon_for_file() function, as
it is obsoleted by gicon_get_icon_for_file().
* gdesktop.c (desktop_icon_info_new): Made it use
gicon_get_icon_for_file().
* gdesktop-icon.c (set_icon): Now we handle things internally
using an imlib image, not a filename.
(desktop_icon_new): Now takes an imlib image for the icon instead
of a filename.
(desktop_icon_set_icon): Likewise.
