Add documentation on ACL requirements for psuedo-attribute entryDN

Also fix up the example for replacing the memberOf overlay
3 jobs for its9121-entrydn in 25 minutes and 13 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #2682
build-gnutls-mit

00:24:52

passed #2680
build-no-threads-no-slapd

00:02:26

passed #2681
build-openssl-heimdal

00:25:13