Unexpected messages in websocket stream
*Created by: ph1l* Hi there, While experimenting with creating a signalk client application, I noticed a bunch of odd messages in the websocket stream. Most of the following messages do not follow the [delta format](https://github.com/SignalK/specification/blob/master/schemas/delta.json) from the spec. ``` $ wsdump ws://raspberrypi:3000/signalk/v1/stream Press Ctrl+C to quit < {"self":"motu","version":"v1.0.0","timestamp":"2016-11-04T20:35:02.751Z"} < {"self":null,"version":null,"timestamp":"2016-11-04T20:35:02.902Z"} < {"vessels":{"motu":{"environment":{"wind":{"angleApparent":{"timestamp":"2016-11-04T20:35:03.104Z"}}}}}} < {"vessels":{"motu":{"environment":{"wind":{"angleApparent":{"value":0.97738438}}}}}} < {"vessels":{"motu":{"environment":{"wind":{"angleApparent":{"values":{"/dev/ttyACM0":{"NMEA0183":{"MWV":{"timestamp":"2016-11-04T20:35:03.104Z"}}}}}}}}}} < {"vessels":{"motu":{"environment":{"wind":{"angleApparent":{"values":{"/dev/ttyACM0":{"NMEA0183":{"MWV":{"value":0.97738438}}}}}}}}}} < {"vessels":{"motu":{"environment":{"wind":{"speedApparent":{"timestamp":"2016-11-04T20:35:03.104Z"}}}}}} < {"vessels":{"motu":{"environment":{"wind":{"speedApparent":{"value":3.5702136}}}}}} < {"vessels":{"motu":{"environment":{"wind":{"speedApparent":{"values":{"/dev/ttyACM0":{"NMEA0183":{"MWV":{"timestamp":"2016-11-04T20:35:03.104Z"}}}}}}}}}} < {"vessels":{"motu":{"environment":{"wind":{"speedApparent":{"values":{"/dev/ttyACM0":{"NMEA0183":{"MWV":{"value":3.5702136}}}}}}}}}} < {"vessels":{"motu":{"environment":{"depth":{"belowTransducer":{"source":{"value":"$SDDPT,3.4,*7E","$source":"unknown","timestamp":"2016-11-04T20:35:03.147Z"}}}}}}} < {"vessels":{"motu":{"environment":{"depth":{"belowTransducer":{"timestamp":"2016-11-04T20:35:03.147Z"}}}}}} < {"vessels":{"motu":{"environment":{"depth":{"belowTransducer":{"values":{"/dev/ttyACM0":{"NMEA0183":{"DPT":{"timestamp":"2016-11-04T20:35:03.147Z"}}}}}}}}}} < {"vessels":{"motu":{"environment":{"depth":{"belowTransducer":{"source":{"value":"$SDDBT,11.5,f,3.4,M,1.9,F*3C","$source":"unknown","timestamp":"2016-11-04T20:35:03.165Z"}}}}}}} < {"vessels":{"motu":{"environment":{"depth":{"belowTransducer":{"timestamp":"2016-11-04T20:35:03.165Z"}}}}}} < {"vessels":{"motu":{"environment":{"depth":{"belowTransducer":{"values":{"/dev/ttyACM0":{"NMEA0183":{"DBT":{"timestamp":"2016-11-04T20:35:03.165Z"}}}}}}}}}} < {"vessels":{"motu":{"navigation":{"speedOverGround":{"source":{"value":"$VWVHW,,T,,M,0.00,N,0.00,K*54","$source":"unknown","timestamp":"2016-11-04T20:35:03.180Z"}}}}}} < {"vessels":{"motu":{"navigation":{"speedOverGround":{"timestamp":"2016-11-04T20:35:03.180Z"}}}}} < {"vessels":{"motu":{"navigation":{"speedOverGround":{"values":{"/dev/ttyACM0":{"NMEA0183":{"VHW":{"timestamp":"2016-11-04T20:35:03.180Z"}}}}}}}}} < {"vessels":{"motu":{"navigation":{"speedOverGround":{"value":0.0}}}}} < {"vessels":{"motu":{"navigation":{"speedOverGround":{"values":{"/dev/ttyACM0":{"NMEA0183":{"VHW":{"value":0.0}}}}}}}}} < {"context":"vessels.motu","updates":[{"values":[{"path":"environment.depth.belowTransducer","value":3.4}],"source":{"value":"$SDDBT,11.5,f,3.4,M,1.9,F*3C","$source":"unknown","timestamp":"2016-11-04T20:35:03.165Z"},"timestamp":"2016-11-04T20:35:03.165Z"},{"values":[{"path":"environment.wind.speedApparent","value":3.5702136},{"path":"environment.wind.angleApparent","value":0.97738438},{"path":"environment.wind.directionTrue","value":0.89011792},{"path":"environment.wind.speedTrue","value":3.6988236}],"source":{"value":"$WIMWV,56.0,R,6.94,N,A*2B","$source":"unknown","timestamp":"2016-11-04T20:35:03.104Z"},"timestamp":"2016-11-04T20:35:03.104Z"},{"values":[{"path":"navigation.speedOverGround","value":0.0}],"source":{"value":"$VWVHW,,T,,M,0.00,N,0.00,K*54","$source":"unknown","timestamp":"2016-11-04T20:35:03.180Z"},"timestamp":"2016-11-04T20:35:03.180Z"},{"values":[{"path":"navigation.position","value":{"altitude":0.0,"latitude":37.8,"longitude":-122.3}},{"path":"navigation.magneticVariation","value":0.239057}],"source":{"value":"$GPRMC,203503.000,A,3752.1021,N,12218.9637,W,0.00,211.88,041116,,,A*78","timestamp":"2016-11-04T20:35:03.302Z"},"timestamp":"2016-11-04T20:35:02.411Z"},{"values":[{"path":"uuid","value":"motu"}]}]} < {"vessels":{"motu":{"navigation":{"position":{"latitude":37.8}}}}} < {"vessels":{"motu":{"navigation":{"position":{"timestamp":"2016-11-04T20:35:03.302Z"}}}}} < {"vessels":{"motu":{"navigation":{"speedOverGround":{"source":{"value":"$GPRMC,203503.000,A,3752.1021,N,12218.9637,W,0.00,211.88,041116,,,A*78","$source":"unknown","timestamp":"2016-11-04T20:35:03.302Z"}}}}}} < {"vessels":{"motu":{"navigation":{"speedOverGround":{"timestamp":"2016-11-04T20:35:03.302Z"}}}}} < {"vessels":{"motu":{"navigation":{"speedOverGround":{"value":0.0}}}}} ```
issue