Add support for Australian numbers

aah, whoops. I just noticed there's a bug in the match for extension. I added a space to the regex but have already stripped them in the code above it so it would never match. Please remove the space from the regex.

  /*
   * strip and save the extension (x9999) postfix if found
   */
  if (preg_match('/(x[0-9]+)$/', $phonenumber, $match)) {
    $extension = ' ('.$match[1].')';
    $phonenumber = preg_replace('/x[0-9]+$/', '', $phonenumber);
  }

We really should get some unit tests made for these.