WIP Starting to work on IPython support for pydy.viz

This PR is created to implement IPython notebook support for visualizations. 
There are going to be two method for display:
`scene.display` and `scene.ipython_display`. If user calls the later one outside the notebook, an error message should be emitted. So to say, `ipython_display()` should **always** be called from inside notebook. `display` can however be called from qt-console or ipython terminal interpreter(basically all other frontends).