(x_delete_display): Call XrmDestroyDatabase.

(x_delete_display): Call XrmDestroyDatabase.

(x_destroy_window): Rewrite to fetch dpyinfo just once.

[USE_X_TOOLKIT]: Make application context explicitly
and support multiple top-level shells.
(x_initialize): Call XtToolkitInitialize, XtCreateApplicationContext;
don't open display or make a shell.
(x_term_init): Call XtOpenDisplay.

(x_scroll_bar_create): Use XMapRaised directly.
(x_make_frame_visible, x_iconify_frame): Likewise.
(XMapWindow): Macro definition deleted.
(METABIT): Macro deleted.
(MAXDESC, FD_SETSIZE, FD_SET, FD_CLEAR, FD_ZERO, FD_ISSET): Likewise.
(x_id_name): Variable deleted.