add pre_htaccess hook; in conjunction with earlier dirwalk_stat

and post_perdir_config hooks, this should allow mpm-itk to be
used without patches to httpd core



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1389339 13f79535-47bb-0310-9956-ffa450edef68