added check for php5-ldap. removed requirement of --force for deleteing all services under machine.

--force used to do two things:
 reset the password for the service account you added if it already existed
 delete all services inside a machine if you asked to delete a machine and they existed

I've removed the later one so it now only resets passwords. If you choose to delete an machine account
i'll assume you want to delete every service inside
updated usage message and changed default host to be ldap.netsoc.dit.ie