Prefer to use normalised signal/slot signatures

Change-Id: Ia5e8866274c6547b142d5b2e4b0309901676aa77
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>
Merge remote-tracking branch 'origin/stable' into dev

Change-Id: I71084828f82b04e60b05d18553a2450bfed2fba1