Synchronized changes of Bullet, from Blender.

Added optional flag btSoftBody::appendAnchor(	int node,btRigidBody* body, bool disableCollisionBetweenLinkedBodies=false), to disable collision between soft body and rigid body, when pinned
Added btCollisionObject::setAnisotropicFriction, to scale friction in x,y,z direction.
Added btCollisionObject::setContactProcessingThreshold(float threshold), to avoid collision resolution of contact above a certain distance.
Avoid collisions between static objects (causes the CharacterDemo to assert, when a dynamic object hits character)

src/BulletCollision/CollisionShapes/btSphereShape.h

@@ -47,6 +47,12 @@ public:
 
 	btScalar	getRadius() const { return m_implicitShapeDimensions.getX() * m_localScaling.getX();}
 
+	void	setUnscaledRadius(btScalar	radius)
+	{
+		m_implicitShapeDimensions.setX(radius);
+		btConvexInternalShape::setMargin(radius);
+	}
+
 	//debugging
 	virtual const char*	getName()const {return "SPHERE";}