starting to implement the game event system (see #12)

the implementation of #6 (player join/leave/etc) events may be based on
the same structure as this (#12)
switching to object keys stored in the box2d objects instead of direct pointers

see #12 (and eventually #6)
Implementing game state logging (see #18). Also fixed config init problem.
fixing the simple renderer a bit

apparently ofxbox2d decided to comment out chunks of the drawing code
ignore zprivate/ so i can keep secrets.

i’m so devious.
added game object creation/destruction logging (see #18)
fixed minor reference issue in the simple renderer
a bunch of work on the game state management and physics

see #3.
Simplified GameObjectionCollection and the way that objects refer to
each other.
Switched GameObjects from having members that are box2d objects, to
directly subclassing those objects, in order to avoid all sorts of odd
pointer issues.
Also, apparently you really need to call setPhysics *before* setup for
the box2d objects… otherwise they don’t move at all. It took me way too
long to figure that out.
Implemented basic mouse control (closes #30)

Also cleaned up a bunch of oddities with pointers and references
Fixed problem with renderer drawing the paddle in the wrong position

box2d coordinates != oF coordinates
Merge pull request #13 from t3kt/master

starting to implement the game event system (see #12)