Deleting LDAP user accounts

For the ZW app we need to delete LDAP user accounts programmatically. Most likely the way to go is adding a method to the LDAPService:

void deleteUser(String username)

It deletes both, the LDAP account, and the DMX Username topic.

@rsc are you able to implement this method? This would be really great.

@jpn @mukil FYI