add the BT_ prefix for all #ifdef guards, to avoid conflicts with developers own header defines.

Fixes Issue 497

//license header
#ifndef BT_RIGIDBODY_H
#define BT_RIGIDBODY_H
class btRigidBody
{
};
#endif //BT_RIGIDBODY_H

src/BulletDynamics/Vehicle/btRaycastVehicle.h

@@ -8,8 +8,8 @@
  * of this software for any purpose.  
  * It is provided "as is" without express or implied warranty.
 */
-#ifndef RAYCASTVEHICLE_H
-#define RAYCASTVEHICLE_H
+#ifndef BT_RAYCASTVEHICLE_H
+#define BT_RAYCASTVEHICLE_H
 
 #include "BulletDynamics/Dynamics/btRigidBody.h"
 #include "BulletDynamics/ConstraintSolver/btTypedConstraint.h"
@@ -232,5 +232,5 @@ public:
 };
 
 
-#endif //RAYCASTVEHICLE_H
+#endif //BT_RAYCASTVEHICLE_H
 

src/BulletDynamics/Vehicle/btVehicleRaycaster.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005 Erwin Coumans http://continuousphysics.com/Bullet/
+ * Copyright (c) 2005 Erwin Coumans http://bulletphysics.org
  *
  * Permission to use, copy, modify, distribute and sell this software
  * and its documentation for any purpose is hereby granted without fee,
@@ -8,8 +8,8 @@
  * of this software for any purpose.  
  * It is provided "as is" without express or implied warranty.
 */
-#ifndef VEHICLE_RAYCASTER_H
-#define VEHICLE_RAYCASTER_H
+#ifndef BT_VEHICLE_RAYCASTER_H
+#define BT_VEHICLE_RAYCASTER_H
 
 #include "LinearMath/btVector3.h"
 
@@ -31,5 +31,5 @@ virtual ~btVehicleRaycaster()
 
 };
 
-#endif //VEHICLE_RAYCASTER_H
+#endif //BT_VEHICLE_RAYCASTER_H
 

src/BulletDynamics/Vehicle/btWheelInfo.h

@@ -8,8 +8,8 @@
  * of this software for any purpose.  
  * It is provided "as is" without express or implied warranty.
 */
-#ifndef WHEEL_INFO_H
-#define WHEEL_INFO_H
+#ifndef BT_WHEEL_INFO_H
+#define BT_WHEEL_INFO_H
 
 #include "LinearMath/btVector3.h"
 #include "LinearMath/btTransform.h"
@@ -115,5 +115,5 @@ struct btWheelInfo
 
 };
 
-#endif //WHEEL_INFO_H
+#endif //BT_WHEEL_INFO_H