increased the test app’s window size to 1024x768
added a stock copy of Box2D 2.3.0
linked Box2D to FallingStuff2Lib
moved Scene.h and Scene.m into the FallingStuff2Lib folder
switched from Box2D 2.3.0 to Chipmunk Physics 6.2.1
cleaned up top-level directory names
added missing Chipmunk Physics files