Removed the RetrievalJob class.

scheduler/CMakeLists.txt

scheduler/MockSchedulerDatabase.cpp

scheduler/MockSchedulerDatabase.hpp

scheduler/OStoreDB/OStoreDB.cpp

scheduler/OStoreDB/OStoreDB.hpp

scheduler/RetrievalFileTransfer.cpp

scheduler/RetrievalFileTransfer.hpp

scheduler/RetrievalJobState.cpp

scheduler/RetrievalJobState.hpp

scheduler/RetrieveFromTapeCopyRequest.cpp

scheduler/RetrieveFromTapeCopyRequest.hpp

scheduler/RetrieveToFileRequest.cpp

scheduler/RetrieveToFileRequest.hpp

scheduler/Scheduler.cpp

scheduler/Scheduler.hpp

scheduler/SchedulerDatabase.hpp

scheduler/TapeCopyLocation.cpp

scheduler/TapeCopyLocation.hpp

xroot_plugins/XrdProFilesystem.cpp