Re: Removing \M-s binding

[...]

> > What about +?  + is currently not bound in wl-summary-mode-map, and
> > it is sort of an obvious choice.
> 
> '-' key is already bound to wl-summary-prev-line-content.  If we use
> '+' for wl-summary-stick, the asymmetricity seems a bit strange to me.

Fair enough; on the other hand, most keys in the summary buffer are unmodified
(M-e and M-E seem to be exceptions).  If we prefer unmodified keys, k is
undefined from the word "stick".