veryDeepCopy

To implement benchmark, I used #veryDeepCopy to duplicate a mesh object. I didn't sure this message works well in croquet world, but it worked with very small fix. Actually, I just only add TObjectFramework >> veryDeepInner: In general, we have to use deep copy carefully for fear of copying unnecessarily objects. Hence, I should test more. But it was enough to use benchmark scripts.