renamed PlayerActionAsset to ActionAsset and moved the AttackAsset class as a member of ActionAsset
added widgets for editing and selection of sets
made the necessary changes to adapt to the ActionAssets class
renames the modified Asset classes
passes platform object as the argument to the COLLISION_BELOW and COLLISION_ABOVE action
improvements to the handling of the behavior when landing near edges.  Pushes the player into the platform a short distance