IE10 WebWorkers

This provides the ability to execute code as a WebWorker.

The performance of this version is abysmal though and definitly not mergeable.
Even though it is a webworker, it locks the UI thread; I'm not sure if something is absolutly wrong with my code though.

Does something in there stick out to someone/@adambom?

This starts the work for issue #12 (new issue since you can't append pull requests to existing issues).