0.01: New App!
0.02: Make overriding the HRM event optional
      Emit BTHRM event for external sensor
      Add recorder app plugin
0.03: Prevent readings from internal sensor mixing into BT values
      Mark events with src property
      Show actual source of event in app
0.04: Allow reading additional data if available: HRM battery and position
      Better caching of scanned BT device properties
      New setting for not starting the BTHRM together with HRM
      Save some RAM by not definining functions if disabled in settings