* uses @inlineCallbacks to turn the _lazy_tail recursion into
a "real" looking loop;
* remove the need for "immediate" vs delayed iteration of said loop;
* make it easier for the unit-tests to control the behavior of the
uploader/downloader;
* consolidates (some) setup/teardown code into the setUp and tearDown
hooks provided by unittest so unit-tests aren't doing that themselves
* re-factors some of the unit-tests to use an @inlineCallbacks style
so they're easier to follow and debug
This doesn't tackle the "how to know when our inotify events have arrived"
problem the unit-tests still have, nor does it eliminate the myriad bits
of state that get added to tests via all the MixIns.
Adds:
- a JSON endpoint
- CLI to display information
- QueuedItem + IQueuedItem for uploader/downloader
- IProgress interface + PercentProgress implementation
- progress= args to many upload/download APIs
