All of the changes needed to get cockpit running on the new 2.5 controller board

Key changes
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* Sensor board support in the Arduino code
* Logging of telemetry data to persistent storage on the browser
* Ability to download telemetry in json
* HUD depth and thrust indicators
* Laser keyboard toggle
* Depth Zeroing button

Given that the 2.4 stable is available in the releases, now seems like a good time to cut over to the master for the 2.5 code. Everything has seemed to work to this point.  The little things can be fixed as we find them.