Fix width/height property assignment during animations.

Fix width/height property assignment during animations.

During animations the behavior of

anchors.fill: parent

and

width: parent.width
height: parent.height

can be different resulting in subtle UI bugs where the final value of a
property is not applied because it is within epsilon of the previous
value. Fixed by directly comparing the width and height instead of
using operator==(QSize, QSize) which does a fuzzy comparison.

Change-Id: I4288b93db2b7baacd9f71ae1932ae743a428313a
Reviewed-by: Andrew den Exter <andrew.den.exter@qinetic.com.au>
Reviewed-by: Gunnar Sletta <gunnar@sletta.org>