Merge pull request #79 from kenvandine/typo

Fixed typo in docstring for Viewport::vScroll
Adjusting README to show how to avoid issue #80

Special thanks to @ricardodovalle for helping us on it.

Signed-off-by: Rodrigo Oliveira <rodrigo@deadbodyoutline.com>
Merge pull request #81 from rodrigogolive/macos_build

Adjusting README to show how to avoid issue #80
Refactored to support qml-box2d's transition to qboject based bodies
and target properties.  Added PhysicsEntity and some Box2D Body/Fixture
convienence components.  Entity and Sprite no longer inherit from Box2DBody.
Cleanup based on review
Fix the fixture geometry in some examples and dropped the gamescene example, it isn't relevant anymore.