Add dependency in Voronoi doc. Add draw_periodic_2_triangulation_2.h

Periodic_2_triangulation_2/doc/Periodic_2_triangulation_2/CGAL/draw_periodic_2_triangulation_2.h

@@ -0,0 +1,15 @@
+namespace CGAL {
+  
+/*!
+\ingroup PkgDrawPeriodic2Triangulation2
+
+Opens a new window and draws `ap2t2`, the `Periodic_2_Triangulation_2`. A call to this function is blocking, that is the program continues as soon as the user closes the window. 
+ This function requires CGAL_Qt5, and is only available if the flag CGAL_USE_BASIC_VIEWER is defined at compile time.
+\tparam P2T2 a model of the `Periodic_2TriangulationTraits_2` concept.
+\param ap2t2 the 2D periodic trinagulation to draw.
+
+*/
+template<class P2T2>
+void draw(const P2T2& ap2t2);
+
+} /* namespace CGAL */

Voronoi_diagram_2/doc/Voronoi_diagram_2/dependencies

@@ -7,3 +7,4 @@ Stream_support
 Triangulation_2
 Segment_Delaunay_graph_2
 Apollonius_graph_2
+GraphicsView