Qt paper doll's depiction of two-handed weapon

When wielding a two-handed weapon, Qt's paper doll shows uwep
in the shield slot as well as in the weapon slot to reflect
that it's occupying both hands.  Make the shield slot's copy
be a mirror image of the weapon's tile so that it looks less
like wielding two weapons.

win/Qt/qt_inv.h

@@ -10,6 +10,9 @@
 
 namespace nethack_qt_ {
 
+// for calls to drawWorn
+enum drawWornFlag { dollNoFlag = 0, dollUnused = 1, dollReverse = 2 };
+
 class NetHackQtInvUsageWindow : public QWidget {
 public:
 	NetHackQtInvUsageWindow(QWidget* parent);
@@ -23,7 +26,7 @@ protected:
 
 private:
         void drawWorn(QPainter &painter, obj *nhobj, int x, int y,
-                      const char *alttip, bool canbe=true);
+                      const char *alttip, int flags = dollNoFlag);
         bool tooltip_event(QHelpEvent *tipevent);
 
         char *tips[3][6]; // PAPERDOLL is a grid of 3x6 cells for tiles