(x_focus_frame, x_focus_event_frame, x_highlight_frame):

(x_focus_frame, x_focus_event_frame, x_highlight_frame):
Delete these vars; now part of struct x_display_info.
(x_new_focus_frame): New arg DPYINFO.  Callers changed.
Use the struct members instead of the globals.
Call x_frame_rehighlight instead of XTframe_rehighlight, so we can
pass on the dpyinfo pointer.
(x_mouse_leave): New arg DPYINFO.  Callers changed.
(XTframe_rehighlight): New arg FRAME.  Callers changed.
Now does all the work in x_frame_rehighlight.
(x_frame_rehighlight): New function, code from XTframe_rehighlight.
(XTread_socket): Use the struct members instead of the globals.
(x_unfocus_frame, x_iconify_frame, x_destroy_window): Likewise.
(x_display_box_cursor, x_make_frame_invisible): Likewise.
(x_term_init): Initialize the struct members.
(x_initialize): Delete initialization of deleted globals.