Merge r728015, r728220, r728020 from trunk:

Merge r728015, r728220, r728020 from trunk:

 *) mod_rewrite: Introduce DiscardPathInfo|DPI flag to stop the troublesome
    way that per-directory rewrites append the previous notion of PATH_INFO
    to each substitution before evaluating subsequent rules.
    PR38642 [Eric Covener]

  axe r->path_info in a more standard way, suggested by Aleksander Budzynowski
  doc typo spotted by Vincent Bray

Submitted By: Eric Covner
Reviewed by: jorton, pgolluci

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@739600 13f79535-47bb-0310-9956-ffa450edef68