Fixed bug where custom onDelete actions could not be created.
Fixed indentation.
Merge branch 'hwloh-onDelete_fix'
Fixed automatic MIME type detection when unpacking archives, added tests for content-based MIME type detection.
Reverted depth limitation for JSON serialisation as it breaks some UI features
Fixed deadlock bug in UpdateCommand, reduced retry count in importer.
Fixed issue #222, the permission flags of dynamic grants are now preserved when a
dynamic type is changed in the schema editor.