Fix cases where events bound to document were 'rebounding'

This fix mostly cases dealing with Turbolinks or anything messing with the ready event. Events bound to the 'document' object were being triggered twice (or more).

Since this method of event binding is independent of the target object existing in the DOM at the moment of it's runtime, it is actually better to leave them out of the ready function.
Doesn't `init_sortable()` **need** to be wrapped in document.ready?