When CSS was set in the head tag then it was not being inherited by the
child tags. This ensures that the inhertiance happens and that the deeper
the CSS is set then it will ensure that it has precedence over the ones
set on the parent.
A test is added that shows the standard inheritance from the head tag and
the precedence from child tags in effect too.
Task-number: QTBUG-28770
Change-Id: I30be3ec141b2cd8d6e0db8a92669aed34da93b33
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>