Use Font-Awesome CDN for font files
Do not re-create the entire navbar when updating

While this does remove the functionality where the new buttons appear and disappear when they're added, that situation is rare and can be handled by a user reloading. The common case of the numbers being reloaded is faster and it doesn't rewrite the links, which was causing issues for J4LP as they host on a non-root path.

It also adds a badge for incomplete requests to the user's button.
Use the actual division ID when there's only one division for submissions

Thanks to @adrien-f for pointing this out to me.
Check that users are allowed to submit to the divisions they're submitting

Security bug: I think the only ill effect would be if users who can only submit to a single division (and that division is not ID #1) their request will go to division 1. This combined with the previous commit should close the error.