some doxygen updates, added some comments to classes, fix broken links, rename some prefix some internal GIMPACT collision structures using (for example use GIM_AABB instead of BT_AAABB),

removed obsolete btGjkEpa (it was replaced by btGjkEpa2 ages ago)

src/BulletCollision/NarrowPhaseCollision/btPersistentManifold.h

@@ -106,7 +106,7 @@ public:
 		return m_pointCache[index];
 	}
 
-	/// todo: get this margin from the current physics / collision environment
+	///@todo: get this margin from the current physics / collision environment
 	btScalar	getContactBreakingThreshold() const;
 	
 	int getCacheEntry(const btManifoldPoint& newPoint) const;