Added support for LOCATE operation

For now, we're ok with accepting client features separate from additions to the server. Getting a full-featured version of Locate to work with the software server, as it stands right now, is pretty involved. I need to spend more time hacking on it before its ready for prime time.

For now, raise a NotImplemented exception in the locate() method and update the locate() method in KMIPImpl to catch this exception, creating a LocateResult object with the appropriate KMIP values, ResultStatus.OPERATION_FAILED and ResultReason.OPERATION_NOT_SUPPORTED.