Embedding with RequireJS

This works, and should take care of line breaks and quotation marks in titles, but.

* I could not find a way to dynamically get absolute URLs into the static build for r.js.  By nature, require's private context prevents reaching in and modifying paths.  r.js does not accept external variables, sadly. Other solution possibilities are definitely welcome; perhaps it hook into the collectstatic action to generate an embed-main based on a template before require runs?
* The `require.conf` module's settings cannot find `REQUIRE_STANDALONE_MODULES` without it being in `viewshare_site_settings.py` (i.e., the most local settings file) and will not find it in other settings files.
* It may be useful to amend Exhibit to take some sort of `loadCss: false` configuration.  It currently goes out to fetch all the CSS already bundled in through Viewshare.  It may also be useful to provide post-setting paths methods.
* There's an open question as to how this will do when interacting with existing Bootstrap / jQuery setups in the pages it will be embedded in.  It shouldn't affect RequireJS setups.