Merge pull request #687 in ZP/z-push from feature/ZP-1372-folder-re-sync-is-triggered-on-deletions-ratio-threshold to develop

* commit '8f1414f0':
  ZP-1372 PHP doc fix - added a dot at the end of the sentence.
  ZP-1372 Created getter ZPush::GetDeviceManager()->GetDevid() , resumed SYNC_STATUS_INVALIDSYNCKEY for triggering a folder resync. Released under the Affero GNU General Public License (AGPL) version 3.
  ZP-1372 Removed logging deviceid. Code style changes.
  ZP-1372 Moved 'Not Triggering folder re-sync' message to INFO level. Released under the Affero GNU General Public License (AGPL) version 3.
  ZP-1372 Folder re-sync is triggered on deletions ratio threshold. Released under the Affero GNU General Public License (AGPL) version 3.