Update Hero.as

Collision angle is get from contact.normal var
Angle verification needed is only 45º to 135º.
normalPoint var is not needed anymore.
Update Box2DContactListener.as

Collision normal is get from world manifold.
Normal and contact points are updated to contact var.
Update b2Contact.as

Added normal and contactPoints vars to be accessed by contact events methods
Merge pull request #78 from Sephius/master

Fix box2d collision angles and contact points reports