groundwork for an interface change

Add a new window-port interface function
     perminvent_info *
     update_invent_slot(winid window, int slot, perminvent_info *);

That should be nice and flexible and allow exchanges of useful
information between the core and the window port. Information
to be exchange can be easily modified in include/wintype.h as
things evolve.

Information useful to the core can be exchanged from the
window-port in struct to_core.

Information useful from the core to the window-port can be
passed in struct from_core.

I'm not going to update any docs until much later after things
are fully working and settled.

This also doesn't fix or have anything to do with existing
TTY_PERM_INVENT issues.

win/Qt/qt_bind.h

@@ -58,7 +58,6 @@ public:
 		const char *str, unsigned int itemflags);
 	static void qt_end_menu(winid wid, const char *prompt);
 	static int qt_select_menu(winid wid, int how, MENU_ITEM_P **menu_list);
-	static void qt_update_inventory(int);
 	static void qt_mark_synch();
 	static void qt_wait_synch();
 
@@ -89,6 +88,8 @@ public:
 
 	static void qt_outrip(winid wid, int how, time_t when);
 	static int qt_kbhit();
+	static void qt_update_inventory(int);
+        static perminvent_info *qt_update_invent_slot(winid, int, perminvent_info *);
 
 	static QWidget *mainWidget() { return main; }