Some rules modifications, pursuant to critique.
Revert "Some rules modifications, pursuant to critique."

This reverts commit 5d137453a98f43c725bc808b564c86b11f6b2c3a.
Starting to modify cover-art display in the template
[Delivers #66237340] Adding a model class for returning whether or not a given entry's cover art exists, and adding an invocation of said model to the past-entries browser.