immediate

• fixes a bug with non browserify builders not getting the mutation observer module

• removes some vestiges that are there for compatibility with setImmediate,vestiges from when it was a shim including
  • ability to pass parameters to the function
  • ability to clear it based on an index
• removes the postMessage hack as there is very little browser usage of it between mutation observer and the faulty IE implementation.

avoid using array shift as that causes performance to plummet.

switches to being a microtask instead of a macrotask

A few tweaks to how mutation observer works mainly based on shadowing what RSVP is doing.

• prevents deoptimizations in v8
• ditches grunt/saucelabs/mocha for npm.scripts/testling/tape