Merge pull request #51 in ASAPO/asapo from feature_worker-api to develop

* commit '68f811c6':
  python producer api arrors as exceptions
  rename worker->consumer
  exceptions instead of errors for worker
  split nodata and end of stream errors
  fix tests
  refactor worker APi errors, remove folder broker
  modified and renamed reset_counter, get_by_id does not reset counter anymore