Only emit focusObjectChanged when an actual change occurs.

Change-Id: If18b460a8773e5cac597c02c51836b79711c20f4
Done-with: Matthew Vogt <matthew.vogt@jollamobile.com>
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Reviewed-by: Alan Alpert <aalpert@blackberry.com>