Improve small screen UI of vehicle control page

[alanwells]

Here are some initial thoughts on improvements that I think could be made here:

• Switch to gyroscopic control of vehicle steering and throttle (instead of nipple.js), as this will free up significant screen real estate for other controls. The DeviceOrientationEvent API seems to have sufficient cross-platform browser support that it could be used reliably on most iOS and Android phones. More info here: https://developer.mozilla.org/en-US/docs/Web/API/DeviceOrientationEvent
• figure out what the "dead zone" of control should be at the middle of the throttle and steering ranges to make it easy to get to zero throttle/zero steering angle without requiring too precise of a device position. i found I had to figure this out with trial and error on an actual device to get a good feel for it
• optimize the layout for widescreen positioning (more intuitive to hold the phone horizontally when you are using the device position as a steering wheel)
• add an easily accessible start/stop button to the screen to avoid the car running off when you set the phone down 😉
• Take advantage of the extra on-screen real estate to include controls for:
  • Pilot mode selection
  • Model selection
  • Start/Stop recording toggle

[wroscoe]

This sounds so much better. Additional control to add is to start and name new session.

I think I'm getting worse ad driving with the current joystick.