various trivial fixes

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
don't pass data as None to request

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
fix log interface

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
use src / dest port numbers

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
another fix

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
aoeu
rewrite metadata sync

Include full and partial metadata sync, but don't worry about tags and
versions. Full and partial sync still have a bit of duplication
that could be factored out.

Save state to disk so partial syncs can know what's already been
synced.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>