Bzr commit on a diverged checkout should suggest push alongside update

[Maciej Katafiasz]

Consider this scenario, just taken from #bzr:

$ bzr co bzr://remote/branch
# hack hack hack
$ bzr commit --local
$ bzr commit
bzr: ERROR: Bound branch BzrBranch7('file:///tmp/checkout/') is out of date with master branch RemoteBranch(bzr://remote/branch/).
To commit to master branch, run update and then commit.
You can also pass --local to commit to continue working disconnected.

What the user actually intended is bzr push, because bzr commit will roll up all the commits into a merge, which is rarely intended. Thus the error message should suggest using push as much as, or maybe more than, update.