Remove or comment out unused variables

Remove or comment out unused variables

* src/w32fns.c (x_set_mouse_color): Comment out variables cursor,
nontext_cursor, mode_cursor, hand_cursor and count.
(x_change_tool_bar_height): Remove variable old_text_height.
(deliver_wm_chars): Remove variable strip_Alt.
(Fw32_shell_execute): Remove variable document_a.
(Fw32_frame_geometry): Remove variable fullboth.
* src/w32term.c (w32_setup_relief_color): Comment out variable
w32_display_info.
(w32_horizontal_scroll_bar_handle_click): Remove variables start, end.
(w32_read_socket): Comment out variables rows, columns.
* src/w32uniscribe.c (uniscribe_check_otf_1): Remove variable rest.