Add support for changing pointer types on Haiku

Add support for changing pointer types on Haiku

* doc/lispref/frames.texi (Pointer Shape): Document that the
pointer shape can now be changed on some window systems other
than X.

* lisp/term/haiku-win.el (x-pointer-X-cursor, x-pointer-arrow)
(x-pointer-bottom-left-corner, x-pointer-bottom-right-corner)
(x-pointer-bottom-side, x-pointer-clock, x-pointer-cross)
(x-pointer-cross-reverse, x-pointer-crosshair)
(x-pointer-diamond-cross, x-pointer-hand1, x-pointer-hand2)
(x-pointer-left-side, x-pointer-right-side)
(x-pointer-sb-down-arrow, x-pointer-sb-left-arrow)
(x-pointer-sb-right-arrow, x-pointer-sb-up-arrow, x-pointer-target)
(x-pointer-top-left-corner, x-pointer-top-right-corner)
(x-pointer-top-side, x-pointer-watch, x-pointer-invisible): New
pointer constants.

* src/haiku_support.cc (BCursor_from_id): Accept int instead of
enum.
* src/haiku_support.h: Update prototypes.

* src/haikufns.c (haiku_create_frame): Stop manually assigning
cursors and set default value of the mouse color property.
(haiku_free_frame_resources): Free custom cursors too.
(struct user_cursor_info, INIT_USER_CURSOR): New struct.
(haiku_free_custom_cursors): New function.
(haiku_set_mouse_color): New param handler.
(haiku_frame_parm_handlers): Add param handler.
(syms_of_haikufns): New cursor shape variables from X.

* src/haikuterm.h: Update prototypes.