In the current German translation, the word "revision" was
translated as both "Version" (translation of "commit") and
"Revision". Since a revision in Git is not necessarily a
commit, we should not translate it with the same word in
order to give the user an idea that it's not necessarily
the same. After this commit, "revision" is consistently
translated as "Revision".

Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>