Add the ldap function to the expression API, allowing LDAP filters and
distinguished names based on expressions to be escaped correctly to
guard against LDAP injection.

Note: this requires at least APR v1.6.0 or above for the apr_escape API.


git-svn-id: http://svn.apache.org/repos/asf/httpd/httpd/trunk@1589986 13f79535-47bb-0310-9956-ffa450edef68
Add the ldap-search option to mod_authnz_ldap, allowing authorization
to be based on arbitrary expressions that do not include the username.


git-svn-id: http://svn.apache.org/repos/asf/httpd/httpd/trunk@1589993 13f79535-47bb-0310-9956-ffa450edef68
Only include the ldap escaping if present within APR.


git-svn-id: http://svn.apache.org/repos/asf/httpd/httpd/trunk@1589995 13f79535-47bb-0310-9956-ffa450edef68