Merge changes I3f815101,Iae2ca70e,I54343e46,I12b8af74,I7eef7827, ...

* changes:
  floss: Cache remote properties on found devices
  floss: Pipe logs to syslog instead of stderr
  floss: GetProperties on enable and cache results
  floss: Replace BtProperty with BluetoothProperty
  floss: Add BluetoothProperty enum variants
  floss: Add ascii_to_string