settings: Avoid "Now visible as (null)" label

If we showed the settings panel before the adapter name
was available.
settings: Avoid spinner + label in row

When cancelling a pair, both the spinner and the label would
visible in the row, instead of just the label.
lib: Downgrade warning to debug
settings: Don't show an error when auth is cancelled

When the user cancels a pairing, we shouldn't show an error.
For now it's just a warning, but could be a dialogue in the future.
settings: Fix PIN confirmation not working
settings: Fix invalid proxy when updating properties

Getting the proxy from the proxy itself won't work...
settings: Fix turning off pairing after connecting

After the connection finishes (whether it works or not), use
the correct argument to turn off pairing.
lib: Coding style fix for connect_callback()
settings: Default test for pairing dialog is confirmation