bug#3717: M-x man completion

[Eli Zaretskii]

> From: Kevin Ryde <user42@zip.com.au>
> Cc: 3717@emacsbugs.donarmstrong.com
> Date: Thu, 26 Nov 2009 09:53:28 +1100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> >
> > This needs to deal with versions of `man' that don't support the -k
> > switch.
> 
> Is the "apropos" program better?

It could be, but it also isn't universally available, especially if
you are on a non-Posix platform.

Ideally, `man' should test what's available, like `grep' does, and if
nothing is, simply not provide this feature.