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

Breaking https://github.com/mozilla/zamboni/pull/1607 up. [Screencast](http://screencast.com/t/d4S8e8Bi9FIf)

**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.**

- If Commbadge waffle is on, use a different template for the reviewer app history table (displays comments, previous review actions, etc).
- Have a JS module that detects if that template is being used, fetch threads + notes from Commbadge API to populate table.

[Part 2](https://github.com/ngokevin/zamboni/commit/a42d10a156bea1315070bb192fcaef2153d66ce4): Display Commbadge attachments along with the notes.

[Part 3](https://github.com/ngokevin/zamboni/commit/4482bd15451bb6b122cac6acf42cd9d8784bbd8c): Create Commbadge notes for all review actions.

[Part 4](https://github.com/ngokevin/zamboni/commit/1605848103a934f1a8d1264d23ad32bf1afdbecc): Create Commbadge attachments from reviewer tools.

[Part 5](https://github.com/ngokevin/zamboni/commit/1d9acc274afe7a7a29d468b4bf78dee6b527ea89): Paginate Commbadge notes if a lot exist for a version.