Proposed by @jsn.sherman

Feature summary: Suppose, while an editor has a page open in VE, a new revision is saved by someone else. Provide a way to merge that revision into the current edit session, using the rich diff information available to resolve conflicts better than can be done on the server side.

Use case(s): Server-side automatic merges fail in many cases, for instance when there are adjacent (but non-overlapping) changes not separated by enough unchanged context.

Benefits: Better automatic merge handling. Better experience for the editor who has invested in authoring a revision. Less chance of inadvertent content loss/corruption during manual merge.