add btActivationCollisionAlgoritm to fix deactivation problems, reported here:

http://bulletphysics.com/Bullet/phpBB3/viewtopic.php?f=9&t=2616

provide access to active objects, requested here:
http://code.google.com/p/bullet/issues/detail?id=128

src/BulletCollision/CollisionDispatch/btActivatingCollisionAlgorithm.h

@@ -0,0 +1,35 @@
+/*
+Bullet Continuous Collision Detection and Physics Library
+Copyright (c) 2003-2008 Erwin Coumans  http://bulletphysics.com
+
+This software is provided 'as-is', without any express or implied warranty.
+In no event will the authors be held liable for any damages arising from the use of this software.
+Permission is granted to anyone to use this software for any purpose, 
+including commercial applications, and to alter it and redistribute it freely, 
+subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+*/
+
+#ifndef __BT_ACTIVATING_COLLISION_ALGORITHM_H
+#define __BT_ACTIVATING_COLLISION_ALGORITHM_H
+
+#include "BulletCollision/BroadphaseCollision/btCollisionAlgorithm.h"
+
+class btActivatingCollisionAlgorithm : public btCollisionAlgorithm
+{
+	btCollisionObject* m_colObj0;
+	btCollisionObject* m_colObj1;
+
+public:
+
+	btActivatingCollisionAlgorithm (const btCollisionAlgorithmConstructionInfo& ci);
+
+	btActivatingCollisionAlgorithm (const btCollisionAlgorithmConstructionInfo& ci, btCollisionObject* colObj0,btCollisionObject* colObj1);
+
+	virtual ~btActivatingCollisionAlgorithm();
+
+};
+#endif //__BT_ACTIVATING_COLLISION_ALGORITHM_H