(mac-utxt-to-string, mac-string-to-utxt)

(mac-utxt-to-string, mac-string-to-utxt)
(mac-TEXT-to-string, mac-string-to-TEXT, mac-furl-to-string)
(mac-TIFF-to-string): New functions.
(mac-text-encoding-mac-japanese-basic-variant):	New constant.
(x-get-selection, x-selection-value)
(mac-select-convert-to-string): Use them.
(mac-dnd-types-alist): New customization variable.
(mac-dnd-handle-furl, mac-dnd-handle-hfs, mac-dnd-insert-utxt)
(mac-dnd-insert-TEXT, mac-dnd-insert-TIFF, mac-dnd-drop-data)
(mac-dnd-handle-drag-n-drop-event): New functions.
(mac-drag-n-drop): Remove function.
(global-map): Bind drag-n-drop and M-drag-n-drop to
mac-dnd-handle-drag-n-drop-event.