Return None on attempt of JSON decode empty string
Encode boolean query parameters in the way CouchDB accepts
Add feeds feature as wrappers over chunked stream response
Implement /_db_updates API call

The usage of db_updates with continuous feed output:

  feed = yield from server.db_updates(feed='continuous')
  while True:
      event = yield from feed.next()
      if event is None:  # nothing more will happen
          break
      # process the event