Remove QQuickItem/PaintedItem wrappers

They were used to hide the differences between QQuick* items and
QDeclarative items when we supported Qt4 and 5.

Now that we've dropped Qt4 support, we don't need theese wrappers
anymore.
updated angrymemes example
make the angrymemes example more dynamic
Better reuse of code in the angrymemes example
Added TrollFace for angrymemes
Add qml-box2d submodule
Removing all Box2D-based items and properties
Initialize Box2D plugin
Added some box2d examples based on qml-box2d
disable building examples and demos that won't work with the switch to qml-box2d
white space fixes
Added the gamescene example back fixed up for the qml-box2d branch
Remove Material entity, it's not used anymore
dropped demo and examples that used old box2d code
Make Entity a subclass of Box2DBody for propery physics integration.  Note they will only have physics if they are a child of a Box2DWorld.  Scene now iterates children of Box2DWorld looking for entities for updates.
Updated ref for qml-box2d submodule
Updated qml-box2d submodule to fix a potential crasher in angularVelocity
removed shapes that are now available as fixtures in qml-box2d
updates for examples based on changes in qml-box2d calculations
Dropped build depends for libbox2d-dev and bump snapshot