7-2: Remove insecure, allow certain writes to posts.

Users can write to posts if logged in.
7-3: Deny access to new posts page when not logged in
7-4: Show a loading screen while waiting to login
7-5: Only show submit post link if logged in
7-6: Use a method to submit the post.
7-7: Sort posts by submitted timestamp.
8-1: Add edit posts form.
8-2 Added basic permission to check the post's owner
8-3: Only allow changing certain fields of posts
9-1 Basic error reporting
9-2: Actually use the error reporting