Improve LDAP Changes plugin with more configurable options

Some LDAPv3 servers are not quite as compliant as we thought. We need to add more configurable options so that different systems can be accommodated for the end user, with possible documentation on which configurations are expected to work for different directories/versions. For example, some servers don't support server side sort, but still work when the control isn't used (eDir); others support sort, but use a different OID (Oracle).