Added the reference to the StartTls factory

git-svn-id: https://svn.apache.org/repos/asf/directory/shared/trunk@1587664 13f79535-47bb-0310-9956-ffa450edef68
Updated the client API to allow the use of the StartTLS operation

git-svn-id: https://svn.apache.org/repos/asf/directory/shared/trunk@1587666 13f79535-47bb-0310-9956-ffa450edef68