bootstrap errors if asciidoc is not installed.

[devnoot]

After checking out the v5.2.2 tag and running ./bootstrap, errors are generated if you don't have asciidoc installed

configure.ac:14: error: possibly undefined macro: AS_IF
      If this token and others are legitimate, please use m4_pattern_allow.
      See the Autoconf documentation.
configure.ac:28: error: possibly undefined macro: AC_DEFINE
configure.ac:30: error: possibly undefined macro: AC_MSG_FAILURE
autoreconf: error: /usr/bin/autoconf failed with exit status: 1

After installing asciidoc, the errors dissapeared.

#65 is possibly related?