setup_tabs

      tab size: <number>

 Modifies the tab setting of the current buffer.

 When the tab key is pressed either a ^I character is inserted or a
 number of spaces is inserted to align the cursor on the next column that
 is a multiple of tab size.

 Initially a buffers tab size setting is determined from its language
 definition. However this call allows it to be subsequently modified.

 The value of the tab setting is displayed at the top right of the screen.

 A tab setting entered as 0, means use real ^I tabs.