.Tab setting.
      Default tab span is 4. It is changed by TAB cmd.
      Tab span is set to each file, and able to set to the directory as default
      by PROfile cmd.
      When insert mode TAB char(\x09) is inserted.
      Column gauge with tab stop id(char "*") allows to set tab stop
      position. It is effective when Rep mode. When insert mode TAB char
      is inserted.
      Refer to COL cmd to set gauge(ruler).