Re: autoconf 2.49c fails if '.' is in PATH

[Akim Demaille]

Well, it's all too messy, and because of this show stopper we are
delaying Autoconf 2.50 way too much.

My personal opinion is 

        back up to test -f

and period.  Sorry for the exotic guys, but no answer seems to have
arose, and yet trying to address this issue screwed the last snapshot.

I will revert the related changes.

But rest assured, there are other releases afterwards :)