pass in reference to actual contact point in cache, rather then temporary value, should fix issue 53

http://code.google.com/p/bullet/issues/detail?id=53
Thanks Alex Silverman for reporting and suggested fix
Changed addContactPoint to lowercase

Extras/BulletMultiThreaded/SpuNarrowPhaseCollisionTask/SpuContactResult.cpp

@@ -150,7 +150,7 @@ bool ManifoldResultAddContactPoint(const btVector3& normalOnBInWorld,
 			(*gContactAddedCallback)(newPt,m_body0,m_partId0,m_index0,m_body1,m_partId1,m_index1);
 		}
 		*/
-		manifoldPtr->AddManifoldPoint(newPt);
+		manifoldPtr->addManifoldPoint(newPt);
 		return true;
 
 	}