2010 October 12 / j|d|a|v|i|s|@|c|a|r|l|e|t|o|n|.|e|d|u
Inherits from Body2D. A body that does no drawing of its own, but rather collects other bodies into a group, so that they act as if they're glued together. All of the collected bodies are drawn with their own colors and textures, but with position, orientation, and scaling all relative to the group's.
Initializes the group with the given list of bodies.
Returns the list of bodies in the group, which the user can alter (append, pop, etc.) as desired, as long as they remain compatible with the renderer.