Simplied code within rdbms namespace

rdbms/Stmt.cpp

rdbms/wrapper/MysqlConn.cpp

rdbms/wrapper/MysqlStmt.cpp

rdbms/wrapper/MysqlStmt.hpp

rdbms/wrapper/OcciConn.cpp

rdbms/wrapper/OcciStmt.cpp

rdbms/wrapper/OcciStmt.hpp

rdbms/wrapper/PostgresConn.cpp

rdbms/wrapper/PostgresStmt.cpp

rdbms/wrapper/PostgresStmt.hpp

rdbms/wrapper/PostgresStmtTest.cpp

rdbms/wrapper/SqliteConn.cpp

rdbms/wrapper/SqliteStmt.cpp

rdbms/wrapper/SqliteStmt.hpp

rdbms/wrapper/SqliteStmtTest.cpp

rdbms/wrapper/StmtWrapper.cpp

rdbms/wrapper/StmtWrapper.hpp