make asides render in studio

Replaces https://github.com/edx/edx-platform/pull/6277 based on master rather than the other branch.

@doctoryes i don't see a thumb from you on either PR
So - is this a Studio-wide config? Or asides-only? The docstring above implies asides-only - but this class name implies Studio-wide. The model should be called what it actually is - to avoid confusion.