Many REST ingest schemes (e.g. Graylog "JSON path from HTTP") expect servers to return well-formed JSON objects.  Floodlight is sometimes returning values that lack root objects.

Was:
   [ <list-of-device-objects>]

Now:
   { 'devices' : <list-of-device-objects> }

Add a debug REST API to get raw device entities.  Fix attachment point blocking code and make it appear in the REST output