[part 1] switch reviewers app history to use comm api (bug 920746)

Breaking https://github.com/mozilla/zamboni/pull/1607 up.

**Part 1: In a waffle, use a separate template for reviewers app history that is populated by the Commbadge API rather than passing in ActivityLog objects through the view.**

Part 2: Display Commbadge attachments along with the notes.

Part 3: Create Commbadge notes for all review actions.

Part 4: Create Commbadge attachments from reviewer tools.

Part 5: Paginate Commbadge notes if a lot exist for a version.