Qt: yn dialog bit

Take care of a Qt TODO:  when using 'popup_dialog' and entering
a count during a yn#aq question, change the default answer button
from 'n' to 'y' since ending the count with <return> accepts it.

win/Qt/qt_yndlg.h

@@ -18,6 +18,7 @@ private:
 	char keypress;
         bool allow_count;
         QLineEdit *le;
+        QPushButton *y_btn;
 
         // abritrary size; might need to be more sophisicated someday
         char alt_answer[26 + 1], alt_result[26 + 1];