Save hundreds of cycles on every autoindex request by _not_ attempting

  Save hundreds of cycles on every autoindex request by _not_ attempting
  to to test the parent (..) sub request!  This patch also allows the user
  to see things that will redirect them.  That way, the lnk or dir within
  the directory is displayed correctly.

  Also allows an ALT text entry other than DIR by providing AddAlt
  ^^DIRECTORY^^, as the user (might) expect to be allowed to do.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@89909 13f79535-47bb-0310-9956-ffa450edef68