HTL: use a binary protocol

[renatobo]

As suggested in the HLT forum message 2 a binary protocol would be best for efficient transmission

Options are

• an existing binary protocol, e.g. Autosport Lab's channel interface design as suggested in message 1
• new one?

Some info in the (HLT developer guide](http://www.gps-laptimer.com/LapTimerDocumentation%20-%20Engine%20Data%20and%20Developer%20Program.pdf)

[renatobo]

at that point, drop NMEA and use uBlox messages directly: a good example is at rc_dyi_tbeam