Description
Updated error codes as per last TC discussion. For operations using identity or index lookup, using an unknown identity or index key value MUST return Not Found. Using an invalid index attribute name MUST return Bad Request.
We talked about Not Implemented at the meeting but that is a server error and using an invalid index is a client error so I used Bad Request
I also added a general note that failure to include mandatory attributes MUST result in Bad Request also. The spec already hinted at this but didn't MUSTify it.
