Delete sage-specific workarounds, wrap in a require.js define

This also uses the new IPython require.js structure ("base/js/namespace") a little.
Make it possible to have a null (transparent) background renderer color
Merge remote-tracking branch 'origin/master' into ipython
Fix a bug where the sprites were ignoring the Object3d properties like position, scale, etc.
Allow the scale.y value to control the scale of a sprite that is scaled to a texture
Update to newest requirejs dependency structure in IPython
Add a SurfaceGrid helper class to draw a mesh on a surface
Better defaults for colors
A common case is to want polygonOffset on, so we default to on.
Update child-handling for newer versions of the widgets in IPython
surface example *is* working
Make a simple setup.py installation file
Merge branch 'ipython' of https://github.com/jasongrout/pythreejs into ipython
Add three.js as a submodule
Add the appropriate require config
Add ipython dependency
Move the nbextension directory
Separate out Sage adapters
Be more careful about what we import at the top level
Make the lights convenience functions not instantiate lights on import