Add Fanout and Status 406 metrics
The following new metrics have been added: status_406, fanout_req_header_bytes, fanout_req_body_bytes, fanout_resp_header_bytes, fanout_resp_body_bytes, fanout_bereq_header_bytes, fanout_bereq_body_bytes, fanout_beresp_header_bytes, fanout_beresp_body_bytes, and fanout_conn_time_ms.
Prior change: JavaScript SDK 0.5.9
Following change: JavaScript SDK 0.5.10
