HOTFIX: Landmark viewing in 3D

The viewing refactoring has broken landmark viewing in 3D. This is
because we did not call the PointCloud viewer before calling
the landmark viewer.

menpo/shape/pointcloud.py

@@ -515,7 +515,9 @@ def _view_landmarks_3d(self, figure_id=None, new_figure=False,
                            group=None):
         try:
             from menpo3d.visualize import LandmarkViewer3d
-            return LandmarkViewer3d(figure_id, new_figure, self,
+            self_renderer = self.view(figure_id=figure_id,
+                                      new_figure=new_figure)
+            return LandmarkViewer3d(self_renderer.figure, False,  self,
                                     self.landmarks[group]).render()
         except ImportError:
             from menpo.visualize import Menpo3dErrorMessage