acversion.in now?

[Tim Van Holder]

Judging by the interesting appearance and disappearance of files in
the repository, I assume someone (presumably Akim) is in the process of
renaming autoconf.sh and friends to .in, I'd like to take this
opportunity to (re-)request that acversion.m4.in be renamed to
acversion.in (multiple dots are a no-no on DOS).