bug#24224: Enable 'h, j, k, l' key navigation where ever possible

[Eli Zaretskii <eliz@gnu.org>]

> From: Mohammed Sadik <sadiqpkp@gmail.com>
> Date: Sun, 14 Aug 2016 12:22:38 +0530
> 
> There are several buffers where alphabet keys have no effect.
> In such buffers, it would be nice to enable the keys h, j, k, and l, for
> navigation, and even further q for quit (or close the buffer), o for
> other window, etc.  This might also help resolve the pinky problem a little.
> 
> The buffers that can include those key for navigation can be
> help-mode, apropos-mode, woman, package-menu-mode (package listings),
> compilation-mode, customize (Custom-mode), info-mode, and so on.

Some of these keys are already bound in some of these modes.  For
example, h and l have bindings in help-mode.

So I guess this could be some optional minor mode, off by default.

Thanks.