Remove double-click and scrolling menu items for scrub/seek...

... Use the toggle button on the ruler instead

src/toolbars/ControlToolBar.cpp

@@ -1258,6 +1258,16 @@ void ControlToolBar::StartScrollingIfPreferred()
 {
    if (PlaybackPrefs::GetPinnedHeadPreference())
       StartScrolling();
+#ifdef __WXMAC__
+   else if (::GetActiveProject()->GetScrubber().HasStartedScrubbing()) {
+      // PRL:  cause many "unnecessary" refreshes.  For reasons I don't understand,
+      // doing this causes wheel rotation events (mapped from the double finger vertical
+      // swipe) to be delivered more uniformly to the application, so that speed control
+      // works better.
+      ::GetActiveProject()->GetPlaybackScroller().Activate
+         (AudacityProject::PlaybackScroller::Mode::Refresh);
+   }
+#endif
    else
       StopScrolling();
 }