Doc: language and standard review

Task-number: QTBUG-32173
Change-Id: I225bc1e4dfe3c12d3441c86002305c542377cf5d
Reviewed-by: Laszlo Papp <lpapp@kde.org>
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Merge remote-tracking branch 'origin/stable' into dev

Change-Id: Iac1dd793d34782bc2d208f17654c4962630d0da7