Merge pull request #211 in ZP/z-push from bugfix/ZP-886-iimportchanges--importmessagedeletion to develop

* commit '0f51a4f3':
  ZP-886 Fix typo. Re-added description.
  ZP-886 Added softdelete flag to ImportMessageDeletion() of: - IImportChanges - ImportChangesCombined - ImportChangesICS - StreamImporter (puts correct tag on the stream!) - ChangesMemoryWrapper.