Perform the merge between two branches incrementally. If conflicts are encountered, figure out exactly which pairs of commits conflict, and present the user with one pairwise conflict at a time for resolution.

git-imerge has two primary design goals:
- Reduce the pain of resolving merge conflicts to its unavoidable minimum, by finding and presenting the smallest possible conflicts: those between the changes introduced by one commit from each branch.
- Allow a merge to be saved, tested, interrupted, published, and collaborated on while it is in progress.