Review code and content outside of merge request flow

Problem

Code review occurs outside the "regular" workflow of creating code for a feature/bug, submitting a merge request, and reviewing the diff. Often, people just want to navigate to a file (or a particular version of it on any given branch), i.e. a commit, and review it, collaborating with other people asynchronously. This also includes the scenarios of documentation review where the docs are tracked through source control in a git repo.

Solutions

• https://gitlab.com/gitlab-org/gitlab-ee/issues/1769 View and add comments on previous commits in text file view
• https://gitlab.com/gitlab-org/gitlab-ee/issues/2478 Comment on any line in commit / merge request diff