This adds `page` to `slug`, and modifies the queries to leverage it.

This has taken the 'get all comments' query from ~400ms to ~48ms.
This fixes #9.
Optimized the recent activity query.

It was needlessly getting the revisions from the DB over and over again when we already had the full list of revisions, sorted.

This fixes #12.
fixed delete.

Now you can delete a page and create a new page at the same url.
Merge pull request #13 from Morgul/ccase-db-improvements

DB improvements