Added better logging of failures to reach catalogue or scheduler.

catalogue/Catalogue.hpp

catalogue/CatalogueTest.cpp

catalogue/RdbmsCatalogue.cpp

catalogue/RdbmsCatalogue.hpp

scheduler/OStoreDB/OStoreDB.cpp

scheduler/OStoreDB/OStoreDB.hpp

scheduler/OStoreDB/OStoreDBFactory.hpp

scheduler/Scheduler.cpp

scheduler/Scheduler.hpp

scheduler/SchedulerDatabase.hpp

tapeserver/daemon/DriveHandler.cpp