settings: Update opened properties when a device changes

Otherwise we'd need to close and reopen it to see updated information.
settings: Fix memory leak when connection fails

The error would be leaked. Also make sure to print the error for
debugging purposes.
settings: More fixes for remote pairing

Send out results for RequestPinCode at the right time (when
the PIN is confirmed, not when a button is pressed after confirmation).
settings: Another coding style fix