Document Editor: Week 5

According to the plan, I had to finish revision control this week. But I'm a little behind the schedule now.

Last week I fixed issues with document listing. It was a pretty tough stuff to implement, cause JSON-based list view supports field prefetching. But it works now and fixed instance has been deployed to appspot. I also started implementation of the view which helps to work with revisions (revert and show diff), but it is still in progress.

This week I plan to finish revision control and start working on diffs.