• When building against 2.4.x, one probably needs to configure without --enable-werror,
  since there were some warnings fixed in Apache httpd trunk.
• Removed obsolete function from interface to mod_ssl. Module now requires at least mod_ssl
  patch v4 in place.
• Fallback certificates has version set and no longer claims to be a CA. (re issue #32)
• MDRequireHttps now happens before any Redirect.
• added some compiler warning flags and adding casts/eliminating some unused params accordingly