Some basic async code in the initialization

Break setUpSurface into a bunch of parts that setTimeout() each other.
This breaks the initialization of the editor as a whole up into the
following phases:
0) Receive AJAX response, parse HTML
1) Build linear model data
2) Build DM tree
3) Build CE tree, CE DOM, create surface
4) Initialize surface, some UI initialization
5) Launch sanity check, remaining setup, unlock editor

This is a bit hacky right now, we'll probably want to refactor later.

ve.dm.InternalList.js:
* Allow construction without a dm.Document

ve.ui.Surface.js:
* Allow construction based on a dm.Document

Change-Id: Ibf48a7e85cd7376c8f6205ed165ff57e71e34c35
Merge "Some basic async code in the initialization"