Smart server fetching update: 7x faster

[Martin Pool]

That's pretty cool.

> There's also a few seconds wasted re-opening the remote branch after the
> revisions are transferred (with both versions of bzr).  I haven't tracked that
> down yet, but that will also improve these numbers.

I saw that too the other day; it also (or as a consequence) seems to
lock/unlock several times when finishing a push, which takes quite a
while.

-- 
Martin