Removed the duplicate SecurityIdentity

common/CMakeLists.txt

common/SecurityIdentity.cpp

common/SecurityIdentity.hpp

nameserver/NameServer.hpp

nameserver/mockNS/MockNameServer.cpp

nameserver/mockNS/MockNameServer.hpp

scheduler/OStoreDB/OStoreDB.cpp

scheduler/OStoreDB/OStoreDB.hpp

scheduler/OStoreDB/OStoreDBFactory.hpp

scheduler/Scheduler.cpp

scheduler/SchedulerDatabase.hpp

scheduler/SchedulerDatabaseTest.cpp