Richard M. Stallman wrote:

>    Yes, we can do this with the external widget feature in the new file
>    chooser.  I will do this after the holidays so we can get some feedback
>    on the actual text.
>
>That is good.
>
>Maybe it could also give help about typing C-l.
>

I've added it now, please take a look and see if it is ok.  I may be a 
bit long.  I've attached a screen shot.