configure.ac

[Akim Demaille]

Would someone see a problem if I adjust Autoconf to support
configure.ac in addition to configure.in?  I think `.in' was a very
bad name (which in addition introduces an undesirable confusion
between autoconf instantiation and config.status instantiation).

The real point is that the day Autom4te (the name is (C) Lars) is
born, it will need means to distinguish between Autotest, Autoconf,
M4sugar and M4sh sources, to load the appropriate frozen files.  Sure
`configure.in' can be reserved for Autoconf only, but adding support
for `configure.ac' seems good anyway.  And to tell the truth, I'd like
to have Autoconf follow this, i.e., rename Autoconf's configure.in as
configure.ac.  I do understand I'm about to shock a few people for
breaking a long established tradition, but when tradition collides
with future, there's no need to think too long (well, I guess someone
will tell me to think longer anyway :).