bug#4362: 23.1: proced -- Mode help lists 'd' as mark command (prefer 'm')

[Glenn Morris]

Juri Linkov wrote:

> But now `C-h m' displays:
>
> m             proced-mark
> d             proced-mark-alt
>
> that causes a false impression that these commands are different.

Perhaps C-h m should merge aliases like where-is seems to do.

> A simpler fix would be just changing the order of `d' and `m' bindings
> in `proced-mode-map' like:

I just copied the undo/advertised-undo approach. Please feel free to
change this as you see fit.