Install some window-size related functions and window-list-1.

Install some window-size related functions and window-list-1.

* window.c (Fwindow_total_size, Fwindow_left_column)
(Fwindow_top_line, window_body_lines, Fwindow_body_size)
(Fwindow_list_1): New functions.
(window_box_text_cols): Replace with window_body_cols.
(Fwindow_width, Fscroll_left, Fscroll_right): Use
window_body_cols instead of window_box_text_cols.

* window.h: Extern window_body_cols instead of
window_box_text_cols.

* indent.c (compute_motion, Fcompute_motion): Use
window_body_cols instead of window_box_text_cols.