In-line Analytics

PR for internal review purposes as prelude for PR to upstream
    PR'd against copy of upstream master.

Known issues to be fixed later:
- Styling is embedded in html file as prelude to re-styling
- No tests
- pep8 and pylint not looked at yet.

@jbau @jrbl @stvstnfrd @caesar2164 if you please.
Also, what about `radio`s and `checkbox`s that use shuffle or random seed or answer pool?  I suspect we want to not handle that case, so we need to detect that.