o updated the handler to reuse the methods by passing the appropriate session handle
o used CoreSession to perform the operation (this is needed to replicate the changes)
o fixed an issue where password cannot be changed if the old password is hashed
o added a test


git-svn-id: https://svn.apache.org/repos/asf/directory/apacheds/trunk@1568502 13f79535-47bb-0310-9956-ffa450edef68