BT2: Some further BT tweaks ...
BT2: playing part 2
tidied up the preference screen: had the categories switched to preference screens.
Preferences: Moved the USB connection type preference to the main screen
Formatting: Automatic formatting of the preferences file
Merge pull request #437 from arthurbenemann/pref

Preference screen ui update
Merge pull request #438 from Paku-/BT2

BT2: BT connectivity works ...
merged with latest from upstream/master