- Refactor UI (use Material Design and new font, drop to single style.xml)
- Do the pump comms using an IntentService in a separate thread
- Add extra OTG check
- General clean up and refactoring (improve naming and code).

Code cleanup and minor refactoring to improve maintainability and the ability to internationalise the app.
Fixes #43

Fix #16 - show registered USB sticks in the registration activity
Fix #14 - show successfully registered devices after CareLink login.

Make only the log part of the UI scrolls.

Fix #6

Remove hardcoded keys.

Removed all options to use Dexcom or Medtronic CGM (sorry arbox0).