TODOs

# TODOs:

X error handling if action throws
X stack tagging
X run
X next/later?
X waterfall
X handle nested runloops
X autorun
X debounce
X coalesce laters/nexts
X cancel
X string methods
X hasScheduledTimers
X better waterfall implementation - cache length, check prior, then compare new length and rerun
X ability to wrap flushes (options) - queue.aroundFlush = Ember.changeProperties

== EMBER TESTS WILL PASS ==

- move ember run loop tests into backburner repo
X remove next
X rename later to setTimeout
X scheduleOnce -> once / deferOnce
X schedule -> defer / enqueue
- schedule run inside actions for async observer support
- default queue
- cancel debounces?
X don't create arrays for actions, push a tuple
- try/finally bullshit
- only tag stack in dev mode
- get rid of Queue#flush - being used by Ember.run.sync
- moar perfs
- clean up string methods handling code?
- merge timers and debouncees arrays?