free memory for btShapeHulls, keep track of it in GL_ShapeDrawer.

move btShapeHull and btConvexHull into its own library in Extras/ConvexHull (it allocates memory using mem/delete and refactoring into using btAlignedAlloc/Free takes too much time)
fix heightfield / btOptimizedBvh for quantization, so that raycast can use quantized aabb (clamp up for maxima and down for minima)

work-in-progress (update projectfiles etc)

Demos/SimplexDemo/SimplexDemo.cpp

@@ -88,7 +88,7 @@ void SimplexDemo::displayCallback()
 		transA.getOpenGLMatrix( m );
 
 		/// draw the simplex
-		GL_ShapeDrawer::drawOpenGL(m,shapePtr[i],btVector3(1,1,1),getDebugMode());
+		m_shapeDrawer.drawOpenGL(m,shapePtr[i],btVector3(1,1,1),getDebugMode());
 
 		/// calculate closest point from simplex to the origin, and draw this vector
 		simplex.calcClosest(m);