vispy/vispy — pull request #384 by Eric89GXL (2014-08-11 21:04:15+00:00)
Title: ENH: Add entity print_tree function

Ready for review/merge. Example output:
```
Omar-2:vispy larsoner$ python examples/basics/scene/viewbox.py
SubScene
+--ViewBox
| +--SubScene
| +--PanZoomCamera
| +--Line: nd box
| +--Line: unit box
| +--Line
+--ViewBox
+--SubScene
+--Line: unit box
+--Line
+--PanZoomCamera
+--TurntableCamera
+--Line: nd box
+--Line: unit box
+--Line: nd box
```