PR#525: there are unprotected opendir/closedir calls in mod_dir.c and

mod_negotiation.c.  Add popendir/pclosedir to deal with them.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@78561 13f79535-47bb-0310-9956-ffa450edef68