Experiment with RenderService decorator with markdown editor

[jeffbcross]

We want to experiment with a way to take a service written as if it was written to be executed in the UI thread, and have it automatically wrapped and executed in UI and worker. @jteplitz602 and I began experimenting with using a monkey-patching decorator to do this: http://plnkr.co/edit/8ksPT8TxTocBkOHvuPP0?p=preview

It's hacky to have a decorator doing so much monkey patching, but would be a good start to figuring out how to make this problem easier to solve in Angular in general.

[jeffbcross]

Related to https://github.com/angular/angular/issues/2409