Add % and \r [C/R] to the dangerous Win32/OS2 characters.

  Retain the Unix sh escapes list for compatibility.
  [William Rowe]


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@94090 13f79535-47bb-0310-9956-ffa450edef68