Performance optimizations in deferred lighting shaders

Created structures for alpha transparency and occlusion culling
Fixed memory allocation issue in KREngine.mm (pointer to NSDictionary allocated on stack retained and later dereferenced when popped)

--HG--
extra : convert_revision : svn%3A7752d6cf-9f14-4ad2-affc-04f1e67b81a5/trunk%4074

KREngine/KREngine/Classes/KRContext.h

@@ -46,6 +46,7 @@ private:
     KRModelManager *m_pModelManager;
     
     std::set<KRNotified *> m_notifiedObjects;
+    std::set<KRNode *> m_allNodes;
 };
 
 #endif