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/BulletMultiThreaded/SpuFakeDma.h

@@ -13,8 +13,8 @@ subject to the following restrictions:
 3. This notice may not be removed or altered from any source distribution.
 */
 
-#ifndef FAKE_DMA_H
-#define FAKE_DMA_H
+#ifndef BT_FAKE_DMA_H
+#define BT_FAKE_DMA_H
 
 
 #include "PlatformDefinitions.h"
@@ -132,4 +132,4 @@ void*	cellDmaGetReadOnly(void *ls, uint64_t ea, uint32_t size, uint32_t tag, uin
 void*	cellDmaSmallGetReadOnly(void *ls, uint64_t ea, uint32_t size, uint32_t tag, uint32_t tid, uint32_t rid);
 
 
-#endif //FAKE_DMA_H
+#endif //BT_FAKE_DMA_H