Note that, while it doesn't really affect the way the application
behaves (as long as the JavaScript code doesn't rely on the order it's
loaded) we're requiring `app/assets/javascripts/custom.js` after
requiring any files in the `app/assets/javascripts/custom/` folder. This
is done for consistency, since we load the content of
`app/assets/javascripts/application.js` after requiring everything else.
