Calculation of bounding box: margins should be added before basis transform.

Disable btSphereBoxCollisionAlgorithm, it is broken.
More fixes for btSimpleBroadphase
Moved quickstep to Extras/quickstep folder, so developers don't get confused which constraint solver is default.

src/BulletCollision/CollisionDispatch/btCollisionWorld.cpp

@@ -127,6 +127,11 @@ void	btCollisionWorld::updateAabbs()
 		{
 			btPoint3 minAabb,maxAabb;
 			colObj->getCollisionShape()->getAabb(colObj->getWorldTransform(), minAabb,maxAabb);
+			//need to increase the aabb for contact thresholds
+			btVector3 contactThreshold(gContactBreakingThreshold,gContactBreakingThreshold,gContactBreakingThreshold);
+			minAabb -= contactThreshold;
+			maxAabb += contactThreshold;
+
 			btBroadphaseInterface* bp = (btBroadphaseInterface*)m_broadphasePairCache;
 
 			//moving objects should be moderately sized, probably something wrong if not