Client-Library enhancements

Unlike DB-Library, Client-Library allows applications to resend RPC commands. The application can resend the RPC command simply by calling ct_send after processing the results of the previous execution. The definition of the RPC command and its parameters remains associated with the command structure until the application calls ct_command, ct_cursor, ct_dynamic, or ct_sendpassthru to initiate a new command on the same command structure.