added notion of boundaries and internal point masses
removed reference ball Entity
added accessors for penetrationThreshold and penetrationCount
removed unused methods in Body
removed unused methods in Layer
first version of renderToTexture for each Layer
extracted combining of Layers in Map
refactored added methods to be private
extracted EdgeSprings and ShapeMatching from SpringPhysics
added stub for EventManager
added test sound for a collectible
make EventManager globally accessible
first version of signal slot principle
added Signals to TriggerFields
connect TriggerField with callback functionality
use Slots to listen on contacts of collectible Bodies
open menu Scene via M
added signum function to Jello.Vector2
added Line class
added getDirectedAngle method to Jello.Vector2