Total rewrite derived from nathan7/pledge.
this brings:
  * a 7% performance increase
  * less code and cleaner code
  * better nextTick handling through timoxley/next-tick
depend on nathan7/next-tick for now
this is for until timoxley/next-tick#5 is merged
Merge pull request #7 from nathan7/pledge

Total rewrite derived from nathan7/pledge.