Autoconf problems, revert?

[Adam Mercer]

Hi

It seems that the update to autoconf-2.66, has caused a lot of
problems. I have so far I have fixed three regressions wrt to 2.65,
but it seems that there are several more: #25509, #25520.

One of the main autoconf developers left for vacation shortly after
the 2.66 release so he won't be able to spend much time looking into
these until he gets back, in about 2 weeks.

I imagine not much is going to happen with regard to getting these
regressions fixed until he gets back, I am therefore proposing to
revert autoconf back to 2.65_1 until these problems can be fixed
upstream.

I'll perform this revert later on this afternoon.

Cheers

Adam