[INTERNAL] P13nCondition/Group/FilterPanel: better group handling added
and other fixes

- property grouping renamed into showIfGrouped
- test page updated
- fixing event handling on P13nXYZPanel

Change-Id: Ibc5a3ecf6a1aa3d933d7214e26335b14c8b46dc2
Merge "[INTERNAL] P13nCondition/Group/FilterPanel: better group handling added and other fixes"