Better implementation of switch from scrub to quick play; ...

... also, don't ever draw the scrub handle while dragging the quick play
region.

src/tracks/ui/Scrubbing.cpp

@@ -501,6 +501,11 @@ void Scrubber::Pause( bool paused )
    mScrubHasFocus = !paused;
 }
 
+bool Scrubber::IsPaused() const
+{
+   return !mScrubHasFocus;
+}
+
 void Scrubber::OnActivateOrDeactivateApp(wxActivateEvent &event)
 {
    if (event.GetActive())

src/tracks/ui/Scrubbing.h

@@ -87,6 +87,7 @@ public:
    static std::vector<wxString> GetAllUntranslatedStatusStrings();
 
    void Pause(bool paused);
+   bool IsPaused() const;
 
 private:
    void DoScrub(bool scroll, bool seek);