Fix middleware error when adding group with children to aggregator
Make optional properties more readable
Restructured and harmonized frontend display of entity properties:
- UUID/middleware are always first
- then required properties (default required are first to make sure Title is always at first position)
- then optional properties (default optional are first)
- optional properties have been reordered to have all display properties together
Merge pull request #117 from andig/sanitize-property-display

Beautify frontend display of properties
Merge pull request #111 from andig/fix-move-aggregator

Fix middleware error when adding group with children to aggregator