The current implementation of the event loop runner has some significant
problems. It can't handle multiple events being emitted at once (for
example, when a keyboard event causes a key input, a text input, and a
modifier change.) It's also relatively easy to introduce bugs for the
different possible control flow states.
The new model separates intentionally emitting a NewEvents (poll
completed, wait completed, init) and emitting a normal event, as well as
providing a method for emitting multiple events in a single call.
