+ Internal improvements for collision shapes

1) add AabbCaching versions of btPolyhedralConvexShape and btMultiSphereShape (this speeds up btMultiSphereShape 'getAabb', and reduces size of btBoxShape)
2) btCylinderShape doesn't derive from btBoxShape anymore
+ Minor fixes in drawing for btMultiSphereShape, btBoxShape.
+ Don't re-generate btDebugFont every frame
+ Disabled velocity prediction for btDbvtBroadphase. Previous default can be restored using btDbvtBroadphase->setVelocityPrediction(1./2.);

src/BulletCollision/CollisionShapes/btMultiSphereShape.cpp

@@ -20,7 +20,7 @@ subject to the following restrictions:
 #include "LinearMath/btQuaternion.h"
 
 btMultiSphereShape::btMultiSphereShape (const btVector3& inertiaHalfExtents,const btVector3* positions,const btScalar* radi,int numSpheres)
-:btConvexInternalShape (), m_inertiaHalfExtents(inertiaHalfExtents)
+:btConvexInternalAabbCachingShape (), m_inertiaHalfExtents(inertiaHalfExtents)
 {
 	m_shapeType = MULTI_SPHERE_SHAPE_PROXYTYPE;
 	btScalar startMargin = btScalar(1e30);
@@ -34,6 +34,7 @@ btMultiSphereShape::btMultiSphereShape (const btVector3& inertiaHalfExtents,cons
 		
 	}
 
+	recalcLocalAabb();
 
 }
 
@@ -149,4 +150,3 @@ void	btMultiSphereShape::calculateLocalInertia(btScalar mass,btVector3& inertia)
 }
 
 
-