Re: etags name collision.

[Stefan Monnier <monnier@iro.umontreal.ca>]

>> Maybe we should install it under a different name, to avoid
>> the conflict but without losing the functionality?
> No, that would be confusing

If we install it under a name like `firefox`?  Yes, no doubt.
But I'm sure we can come up with a sane enough name to avoid this problem.

> and will break those who do still use our ctags.

Yes, that's the main downside.
But it'd be a small matter of adding an alias or symlink, so it's not
that bad.

> I think detecting that another kind of ctags is installed is the best
> and safest way to have the cake and eat it, too.

Rather than "install vs not-install" the test could decide "install as
`ctags` vs install as `somethingelse`", which is closer to having our
cake and eating it too since the user can then have both installed at
the same time.

Still, an install-time test has the downside that it won't adapt if
`ctags` is installed after Emacs is built/installed, as is probably the
case for most users nowadays (who don't build Emacs themselves but
install from a distro or from our prebuilt tarballs).

AFAICT it won't make a big difference for GNU/Linux distros since these
already go through the trouble of renaming our `ctags` (it might just
make their job a bit easier and avoid inconsistencies between distros
where every distro may choose a slightly different name).

BTW, regarding the state of our `ctags` compared to the other ones.
A few years back I remember someone comparing them and finding out that
we support fewer languages but that for some of those languages we
provided better results.  If that's not the case any more, maybe we
should check to see if we could make `etags.el` use "Exhuberant ctags"
when available so as to benefit from the better tool.


        Stefan