[plt-scheme] MrEd: Multi-column list-box?

Dear Schemers,

Thanks for all the input on DB bindings...I'm still evaluating the 
options and compiling. :-)

Another question: Is there a multi-column list-box in MrEd? I've seen 
some kind of hand-woven one in SirMail, but wasn't able to find its 
implementation in SirMail's source.

Before I fill out a feature request, I'd like to know whether I perhaps 
missed something and standard multi-column listboxes are already 
available in v299. I'm talking about those resizable, often sortable 
multi-column boxes you e.g. can find in Apple Mail's main window on OS 
X. They seem to be fairly standard in most GUI/Window Managers 
nowadays.

Also: Should people generally fill feature requests for things like 
that, or is it enough to mention it on the mailing list? In my 
experience, the policy on the use of bug tracking systems differs from 
developer community to developer community. What's PLT's?

Best regards,

Erich