Descriptive subjects

[Joel Brobecker]

> +1. In fact, I would even suggest that we follow that guideline
> for revision logs as well. When going through the log trying to
> identify the commits that might be responsible for a change in
> behavior, "PR bla/12345" is not very helpful for that.

Something that occured to me a little after I sent the email:
I suspect that using the PR's subject would often work as a good
subject for the commit.

-- 
Joel