> This seems more of a short comming in `bzr log --short' than in
   > the way one writes commit messages.  A commit message is more
   > than a single line.  And the purpose of a change is always more
   > suitable in the actual code as a comment.

   You're conflating quite different things. If I update my tree with
   "bzr up", obviously I'm not going to go looking at the code to know
   which changes were made, but I certainly will do "bzr log --line
   -l10" to see recent changes and their purpose.

That is the whole idea of a ChangeLog, a short message doesn't
substitute it.