bug#68274: automake 1.16j nonnumerical version confuses scripts

[Karl Berry]

    there is nothing requiring or restricting the current version behavior
    other than "it's always been this way".  

True.

    but that doesn't mean it's better.

No way to know what release or test scripts might be relying on the
current convention. Changing for the sake of change doesn't seem good.

    there's no reason we couldn't use more modern convention here like -rc#.

I don't much like it, since "rc" always makes me think first of rc
files. It also wouldn't fix the problem in jami (still not numeric).

Another alternative: when this came up 30-odd years ago, rms changed the
GNU maintainers doc to suggest x.y.90, .91, etc. for pretests. Doing
that would at least have the benefit of following a recommendation, and
as a side effect, would also fix jami's assumption (poor practice though
it is, IMHO).
https://gnu.org/prep/maintain/html_node/Test-Releases.html#Test-Releases

Doing an ls -R on alpha (fp:/srv/data/ftp-mirror/alpha/gnu), it seems
(rough guess with some grep counting) the .90 convention is by far the
most common approach (a couple thousand), followed by the suffix letter
a la automake (~750 releases), followed by -rc (~360). -hexid and -date
are both trailing the field. Other random conventions also present.

It all feels like bikeshedding to me, so my inclination is to do
nothing.  If we do change, I think we should use .90.  --best, karl.