autoreconf 2.62 can't handle AS_VAR_IF in our configure.ac
configure.ac:607: error: possibly undefined macro: AS_VAR_IF If this token and others are legitimate, please use m4_pattern_allow. See the Autoconf documentation. autoreconf-2.62: /usr/local/bin/autoconf-2.62 failed with exit status: 1
http://www.winehq.org/pipermail/wine-devel/2010-May/083662.html indicates that autoreconf 2.62 can't handle AS_VAR_IF.
We introduced AS_VAR_IF in two places in git commit 21ac2928 which went into Tor 0.2.5.2-alpha.
If this is easy to fix, it seems wise to do so -- we have some relays (including at least one directory authority) that are still on autoreconf 2.62.