Comments, Datetime, Author Name Added

First, I added who posted each post on the main page. Then, since I had
already added the timestamp, I formatted it. We don't need to know when I
posted to a precision of seconds to five decimal places. Finally, I added
Disqus comments.

To do:
- Add a categories table, as well as a category column in the posts table.
- Add a list of categories in the navigation panel.
    - This will necessitate a new template for displaying posts from a certain
      category
- Add the ability to edit a post's category in /post/edit.
- Finish styling the site.
- Eventually add the ability to modify users.