Improved merge request comparison and revision picker

Problem to solve

After opening a merge request and viewing the diff, it isn't possible to switch to a commit by commit revision without first going to the commits tab to select a commit. Even then, every time I want to change to a specific commit I need to go the commits tab. Also, when I want to switch back to see the combined diff there is no easy way to do this.

Further details

Review Board has a slider interface for the reviewer/reviewee to diff between review rounds by sliding back and forth in time. Specifically, if you participated in a few rounds and then jump in later, you can see what’s new without cluttering with the old.

Version 0 (merge base) to Version 2 (HEAD)	Version 1 to Version 2 (HEAD)

Proposal

Improve the interface of our revision and commit selection interface in the merge request.

What does success look like, and how can we measure that?

(If no way to measure success, link to an issue that will implement a way to measure this)

Links / references

• ReviewBoard demo: http://demo.reviewboard.org/r/5/diff/1-2