Persistence - Polishing Up

The main reason for this pull request is that I've added styling to the DiffReport. The HTMLDiffReport changed slightly, I added another container for styling purposes. Otherwise, this pull has many changes to the Persistence tests, I've added more tests to significantly increase the code coverage on the Persistence packages.

Please note that I've merged the GUI-and-Persistence branch into this one. I made a change to the DiffReport html after merging the two for testing and I wanted to commit that as well.