Fix T40344: Levels of Detail not smooth with Armature Modifier

Due to skinning changes for multi-threaded animations, the LOD check was
being done after skinning. Now the LOD check is run before animations.
This means the culling information is a frame old, but this should be
fine.
Fix T40387, image api save and pack did not fire notifiers.
Fix T40362: Projected texture from spotlight doesn't scale with spotsize when changed in-game via Python

GPULamp::winmat needs to be updated after the spot size has changed.
BGE cleanup: Remove unused KX_TrackToActuator::m_tracktime member.
BGE cleanup: Removing some potential memory leaks from KX_NavMeshObject when it fails to build a navmesh.
BGE: Accidentally committed some debug code in 8dafbe.
Fix 40343: Using replace mesh (e.g., LODs) on a skinned mesh crashes.

Need to use parent->AddRef() in a few places.