end latency detection if AMS window closed while running detection (plus some non-functioning changes to try to get spinbutton text entry to work
a few DEBUG_TRACE improvements
check for an existing PublicEditor instance AFTER attempting to handle a key press in a window that has called relay_key_press(), so that normal key handling works there (e.g. audio/MIDI setup)
minor fixups for audio/MIDI setup spin buttons (now editable, as they should be)