Add new nextTick implementation to Utils class.

[ashleysommer]

Add new nextTick implementation to Utils class This is apparently much faster in some workloads. It yielded a small improvement in performance in my application. I feel that this is a much clear implementation than the message post method, so I have given this higher priority for browsers which have native Promises. See here for more information: http://blog.millermedeiros.com/promise-nexttick/