qdoc: Allow QML linking without version nr

This change allows links of the form:
\l{qml-module-name::qml-type}{name}
i.e. no version number provided.

This change does not handle collisions.
There aren't any in Qt5 at the moment.
If a collision occurs, qdoc will link to
the name in one of the colliding QML
modules, but not necessarily the most
recent one. Hence, the link may go to
the wrong page. A further update might
be forthcoming that will handle this
better.

Task-number: QTBUG-29778
Change-Id: Ie2c2b117446ed02852593dd0273c390d39fed927
Reviewed-by: Venugopal Shivashankar <venugopal.shivashankar@digia.com>
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Windows: Repaint when switching off layered windows by opacity.

Task-number: QTBUG-29010

Change-Id: I565a800e5a5b4870bd3ee2e3fb3f55523334425f
Reviewed-by: Andy Shaw <andy.shaw@digia.com>
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
Fix spelling

Change-Id: If3d5e09b2553d95caacd3e61a1bb108f1172111f
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>