TBD Version 0.5a;
AbstractConstraint.resolve() is now public so it can be overridden (thanks to Interfaced)
CollisionEvent class with COLLISION and FIRST_COLLISION events.
AbstractItem now extends EventDispatcher.
Added a new property 'solid' similar to collidable, but allows collision events to be triggered.
Changes to the AbstractCollection and Group classes to allow safe removal of children during the collision testing cycle
Fixed a bug where SpringConstraintParticle was not returning the fixed property correctly.


06-21-07 Version 0.45a
Two new properties for much greater stability - constraintCycles and constraintCollisionCycles
Group now takes collideInternal setting as a parameter in the constructor.
Fixed a bug where certain particles/constraints would be drawn before their parent hierarchy was added to the engine
Corrected misc documentation errors/omissions
New Demo - walker robot


06-01-07 Version 0.4a
Changed license to MIT
Groups added. 
Composites added.
Fixed a bug with SpringConstraint restLength <= 0. Thanks to Robert Brisita.
Added a base class, AbstractItem, the parent of both constraints and particles for better OOD
Fixed particles are no longer repainted, unless new property 'alwaysRepaint' is true  -- improves performance
Some performance tweaks, especially with loops.
The 'container' property for particles and constraints renamed to 'sprite', for clarity.
The APEngine.container property is now of type DisplayObjectContainer, not Sprite.
Renamed 'rotation' to 'radian' in RectangleParticle to be consistent with SpringConstraint. Thanks to Robert Brisita
Removed corner particles and edge particles due to grouping issue. The same effect can be recreated with Composites, or Groups



05-02-07 - Version 0.3
Improvements to the SpringConstraint including much better collision response
Many API additions for easier painting and attaching DisplayObjects
Fixed a bug with adding forces. AbstractParticle.addForce() was altering the 'force' array in APEngine.
Changed the default painting methods to be faster and better designed.
Painting cycle is now managed by APEngine, not the user.


10-13-06 - Version 0.2
Initial release