Make events look like events

[KidkArolis]

There are a couple of events in the routes: willTransition, error and queryParamsDidChange - consider making it explicit that they're events by putting them into route.events.willTransition or so like the original router.js does it.

Events are special in that they're called from the right most route to the top, and the propagation of them can be stopped so it's worth making them look different from the rest of the hooks.

[KidkArolis]

Not relevant in 2.0.0