Introduced btActionInterface. This makes it easier to extend user-defined actions, such as vehicles and characters.

btRaycastVehicle and btKinematicCharacterController are derived from btActionInterface now.
Some cosmetic cleanup: changed sourceforce/sf.net url to bulletphysics.com.

Demos/RagdollDemo/main.cpp

@@ -27,5 +27,5 @@ int main(int argc,char* argv[])
         demoApp.initPhysics();
 		demoApp.getDynamicsWorld()->setDebugDrawer(&gDebugDrawer);
 
-        return glutmain(argc, argv,640,480,"Bullet Physics Demo. http://bullet.sf.net",&demoApp);
+        return glutmain(argc, argv,640,480,"Bullet Physics Demo. http://bulletphysics.com",&demoApp);
 }