It's common practice for "merge" commits to have the form:
"merge work from some/branch, fix PR #somenumber".
This basically tells me nothing about what this commit does.
We already know it's a merge commit, we don't care so much what
branch it's from, and we don't want to dig into the bug tracker
to translate the issue number into english.
We care more about how this merge modifies the code behaviour.
What if "merge" commits had better messages, not containing the
word "merge" at all?
This way, the depth-0 history, which is always linear, would be
human-readable and bisectable.
