t use the cursor specified for the frame
nil don't display a cursor
+ box display a filled box cursor
+ hollow display a hollow box cursor
bar display a vertical bar cursor with default width
(bar . WIDTH) display a vertical bar cursor with width WIDTH
hbar display a horisontal bar cursor with default width
(hbar . WIDTH) display a horisontal bar cursor with width WIDTH
- ANYTHING ELSE display a box cursor.
+ ANYTHING ELSE display a hollow box cursor.
When the buffer is displayed in a nonselected window,
this variable has no effect; the cursor appears as a hollow box. */);