Merge pull request #145 in ZP/z-push from feature/ZP-818-send-no-answer-collection-for-unchanged to develop

* commit '5179ec79':
  ZP-818 Omit folder output on unchanged folders for AS 14.0 and higher.
  ZP-818 Supress collection containers if there are no changes for a folder, refactored code having the actual export and streaming of data in a private method.