AthExThinning → StoreGate Relation

File in Control/AthenaExamples/AthExThinning/AthExThinning	Includes file in Control/StoreGate
WriteThinnedData.h	StoreGate / StoreGate/StoreGate/ReadHandleKey.h
WriteThinnedData.h	StoreGate / StoreGate/StoreGate/ReadHandleKeyArray.h
WriteThinnedData.h	StoreGate / ThinningHandleKey.h