Removed duplicate include statements from several packages in Control

Control/AthAllocators/AthAllocators/Arena.h

Control/AthenaExamples/AthExHive/src/HiveAlgC.h

Control/AthenaExamples/AthExHive/src/condEx/ASCIICondDbSvc.h

Control/AthenaMPTools/src/AthenaMPToolBase.cxx

Control/AthenaMPTools/src/SharedHiveEvtQueueConsumer.cxx

Control/AthenaServices/src/AthenaHiveEventLoopMgr.h

Control/AthenaServices/test/AthenaEventLoopMgr_test.cxx

Control/IOVSvc/src/CondSvc.h

Control/SGComps/src/SGFolder.cxx

Control/StoreGate/StoreGate/StoreGateSvc.h

Control/StoreGate/StoreGate/tools/SGImplSvc.h

Control/StoreGate/src/SGImplSvc.cxx

Control/StoreGate/test/VarHandleBase_test.cxx