Updating rebase help

[Matt Mackall]

On Wed, 2013-01-30 at 14:10 +0100, Pierre-Yves David wrote:
> I'm going to update the rebase help to refer to the --rev option. But I think
> the help could use a more generic update.

Let's sit on this for post-2.5. The translators get a little grumpy when
we do bulk text edits in the last couple days of the freeze.

-- 
Mathematics is the supreme nostalgia of our time.