window-port updates

Remove start_screen() and end_screen() from the
Window-port interface.

They were only ever used by tty, and there was a comment
carried to several window-ports about how they "really
should go away. They are tty-specific"

term_start_screen() and term_end_screen() are part of
terminal/NO_TERMS supporting routines now.

win/Qt/qt_bind.cpp

@@ -966,16 +966,6 @@ NetHackQtBind::qt_get_color_string(void)
 
 #endif
 
-void NetHackQtBind::qt_start_screen()
-{
-    // Ignore.
-}
-
-void NetHackQtBind::qt_end_screen()
-{
-    // Ignore.
-}
-
 void NetHackQtBind::qt_outrip(winid wid, int how, time_t when)
 {
     NetHackQtWindow* window=id_to_window[(int)wid];
@@ -1232,8 +1222,6 @@ struct window_procs Qt_procs = {
     nethack_qt_::NetHackQtBind::qt_get_color_string,
 #endif
     /* other defs that really should go away (they're tty specific) */
-    nethack_qt_::NetHackQtBind::qt_start_screen,
-    nethack_qt_::NetHackQtBind::qt_end_screen,
 #ifdef GRAPHIC_TOMBSTONE
     nethack_qt_::NetHackQtBind::qt_outrip,
 #else

win/Qt/qt_bind.h

@@ -85,8 +85,6 @@ public:
 	static int qt_get_ext_cmd();
 	static void qt_number_pad(int);
 	static void qt_delay_output();
-	static void qt_start_screen();
-	static void qt_end_screen();
 
         static void qt_preference_update(const char *optname);
         static char *qt_getmsghistory(boolean init);