fixes #1367

This is my proposed fix for #1367. @martypdx could you take a look at this when you get a chance please? It affects lifecycle hooks, and I want to make sure I'm not doing something wrong here.

Rather than firing `render` hooks *before* `runloop.end`, this schedules it for later, when all views have been updated - so any given component's `onrender` hook is guaranteed to only fire once the DOM is in sync with Ractive.