elaborate on per-directory limitations



git-svn-id: http://svn.apache.org/repos/asf/httpd/httpd/trunk@1643034 13f79535-47bb-0310-9956-ffa450edef68
xforms


git-svn-id: http://svn.apache.org/repos/asf/httpd/httpd/trunk@1643035 13f79535-47bb-0310-9956-ffa450edef68