Create basic Sampling view

[frankleonrose]

(Look at #1 for a brief discussion of the approach to viewcontrollers I'm imagining.)

[
  authentication: [
    email: "[email protected]"
    service: "github" // or google, twitter, facebook - a decent choice of 3rd party OAuth2 identity providers
  ]
  currentLocation: lat/lon (if tracking, will remain in center of map, otherwise could be on or off map) 
  collecting: [
    device: devID
    devicePicker: true/false - whether to show expanded device picker
    started: time
    packets: 123
    received: 120
    state: Play/Pause/Stop (when paused, pause button shows as play icon)
    scrollToSample: sample seq no OR -1 for auto-scroll as samples come in
    mostRecentSample: [lat: Y, lon: X, rssi: -100, snr: 4, seqno: 123, timestamp: time, device: devID]
    samples: [
      [lat: Y, lon: X, rssi: -100, snr: 4, seqno: 1, timestamp: time, device: devID],
      [lat: Y, lon: X, rssi: -100, snr: 4, seqno: 2, timestamp: time, device: devID]
      ...
    ]
  ]
]

The messages from this view are:

• Login - user wants to get authenticated in order to use API for tracking
• Logout - user wants to logout, presumably to login with a different email or service
• Open device picker - user has tapped device to open device picker
• Pick device - user has chosen a device from the picker
• Start - start collecting
• Pause - pause collecting
• Stop - stop collecting
• Scroll to sample - user has scrolled to view a particular sample. Keep it in view.

(The sketch image is my way of thinking about and identifying the information we want in the view. The layout represented is not totally unreasonable as a starting point for implementation, but there is a lot of room for improvement. Please change arrangement, spacing, color, and content as much as you like to be more awesome.)