USB devices perms, nth device feature, code cleanup

- add ability to query for usb device permissions
- add open nth device feature
- refactor ElmInterface to remove direct settings access (cleaner
seperation of components)
improved button debounce, cleaned up comments, code cleanup
readme clarifications & formatting
improved debounce
added CHANGELOG.md and fixed app version
readme correction
added device-protocol and monitor-command to settings
Merge branch 'release/v1.1'