Language Selection

Fixes #144. This adds a language selection dropdown to the footer which allows the user to change their language which will result in changing the site content. This will also make it clear that #160 is not an issue.
I've deployed this in an integration branch on dev, and this isn't firing in chromium or firefox. Perhaps this needs to be on `blur` instead of `change`? I tried this from the dev console and it seemed to work, in that the function did get called. However, even when calling `$('#language-form').submit();` on blur or directly, that doesn't seem to be sufficient to fully change the language on the site -- leaving aside the obvious fact that we don't actually have translated strings in the db, shouldn't the URL change to the new locale?