o Minor bugfixes:
    - When building the manpage from a tarball, we required asciidoc, even
      though the asciidoc -> roff/html conversion was already done while
      building the tarball. We now make it so that make complains when
      we need asciidoc (either because someone is compiling directly from git,
      or because they altered the asciidoc manpage in their tarball). Bugfix
      on 0.2.2.9-alpha.