Minor languages changes + Voting update

Hey Damien,

I've made a few changes to the wording on the site (mostly to adjust for what sounds correct/natural). Feel free to discard any changes you don't agree with.

I've also noticed that the double-click behaviors on up and down votes were different. I'm not sure if that was by design, but it felt a little odd, which is why I've adjusted the downvotes double-click behavior to match that of upvotes (i.e., double-clicking would _"undo"_ a vote).