Initial embed implementation and example.

Adding embed component `glmol_embed`, which renders a pdb and
representation via a javascript display object.

`GLmol` library is rendered from GLmol submodule and saved into the
current profile's `static/` file directory. Current model should be
used for development deployments, code is re-rendered and overwrites
/static/glmol on every invocation. Should perform CDN (or github pages)
deployment of rendered library and update include path for named
tagged releases.

Added simple embed example notebook.