V4: remove unused field.

Change-Id: Id1edc073db349cfc7e4b5a9dca045760016ebacf
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@digia.com>
Fix crash in header when regenerating view.

Unregister for geometry changes before reparenting, as
reparenting may trigger those changes.

Task-number: QTBUG-36481
Change-Id: Ia94f1f88880b232dd583b7e63e5da73fb338f7c6
Reviewed-by: Martin Jones <martin.jones@jollamobile.com>