Editing posts - views and stuff

 - Added an 'edit' link when viewing a post. You need to be authenticated to click it.
 - Added an edit view; you can't yet save the post, though.
Editing posts; lightweight session store.

Still haven't finished the post edit story -- changes aren't getting persisted.

But I got fed up with having to log in every time my app restarted.
Given that I'm (currently) on Windows, I can't really use connect-redis,
so I wrote a quick REST-based key/value store using plain node.

The client's included here (for now), and the server's in another repository.
Implemented editing/versioning of posts.
Editing articles.

The code to edit articles needs a custom ID field: add the migration script.