Qt prompt highlighting

When qt_yn_function() or qt_more() is asking for a single character
response, typing anything will cause the prompt line in the message
window to stop being highlighted.  If they reject what's been typed,
they beep (--More-- doesn't start beeping until second rejection);
change both of them to also rehighlight the prompt line to give a
visual indication that the question/acknowledgement is still being
asked.

win/Qt/qt_msg.h

@@ -30,6 +30,7 @@ public:
 
 	void setMap(NetHackQtMapWindow2*);
 
+        void RehighlightPrompt();
         bool hilit_mesgs();
         void unhighlight_mesgs();
         // for adding the answer for yn() to its prompt string