ADD: ItemFormFieldsPartial can now be configured
Merge branch 'develop' of github.com:YAG-Gallery/yag into develop

* 'develop' of github.com:YAG-Gallery/yag:
  CHG: Added an example for a custom media data element
  Fix: Fixed the Drag n Drop sorting
  [FEATURE] AlbumViewHelper now also accepts the gallery as parameter
  FIX: Tests: DefaultTsConfig now includes importFileMask
  FIX: importFileMask in config object
  TASK: Refactored CSS files
  TASK: removed standalone theme
  DEL: Removed unused css files
TASK: Removed unused Code form Classes/Utility/Flexform/RecordSelector.php