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.
To put this concretely, I'd like to see `correct_response`,`num_choices`, and `choice_text` all be populated here with just a call to a capa library function.