C-h k could display the binding key map

[David Reitter]

Here's an idea from a user.

Begin forwarded message:

> From: Tom Van Vleck <address@hidden>
> Date: 24 September 2008 11:41:03 EDT
> To: Emacs on Mac OS X Mailing List <address@hidden>
> Subject: Re: [OS X Emacs] Aquamacs Emacs 1.5 released
> Reply-To: Emacs on Mac OS X Mailing List <address@hidden 
> >
...
> Finding out what keys are bound to, using C-h k, leads to another  
> issue.  The popup shows what the key is bound to, but not WHY.  That  
> is, the binding could be the result of the aquamacs-key-map, or of  
> one of many modes.  Would it be possible to display what mode bound  
> the key?