Improve timingView with display of the ASS lines

Display the Ass lines on the timingView.

Allow for Drag & Drop of bars to change syl duration / line start and end time of the AssLineModels only (as changes are not written back to the Ass file yet).

src/UI/DocumentViews/AudioVisualizer/TimingAxis.hh

@@ -6,6 +6,7 @@
 #endif
 
 #include "PreCompiledHeaders.hh"
+#include <cmath>
 
 namespace Vivy
 {