Let's make semitrusted+:1 mean that, since it cannot be expressed easily
with the current syntax (could use (semitrusted:1 or trusted:1), but that
does not scale to higher values than 2 copy, and also fails if I add more
trust levels).
Thanks to Andy for spotting this bug by just reading my blog.
When there's just 1 client repo, and a transfer repo is created, its
preferred content will now make it prefer all content in the client,
even though there's no other client yet to transfer it to. Presumably,
another client will be created eventually. It might even already exist,
and the transfer repo will be used to connect up with it.
