Don't encode command options as part of accelerator string...

... also restore the intended meaning of "allowDup" (for debugging checks only),
which had never been properly implemented because the label, not the
accelerator, was scanned for it; see commit f2f7568

src/tracks/ui/Scrubbing.cpp

@@ -1259,10 +1259,12 @@ BaseItemSharedPtr KeyboardScrubbingItems()
    Items( wxT("KeyboardScrubbing"),
       Command(wxT("KeyboardScrubBackwards"), XXO("Scrub Bac&kwards"),
          &Scrubber::OnKeyboardScrubBackwards,
-         CaptureNotBusyFlag() | CanStopAudioStreamFlag(), wxT("U\twantKeyup")),
+         CaptureNotBusyFlag() | CanStopAudioStreamFlag(),
+         Options{ wxT("U") }.WantKeyUp() ),
       Command(wxT("KeyboardScrubForwards"), XXO("Scrub For&wards"),
          &Scrubber::OnKeyboardScrubForwards,
-         CaptureNotBusyFlag() | CanStopAudioStreamFlag(), wxT("I\twantKeyup"))
+         CaptureNotBusyFlag() | CanStopAudioStreamFlag(),
+         Options{ wxT("I") }.WantKeyUp() )
    ) ) };
    return items;
 }