Qt: add tool tips for status window icons

Show a tip if the mouse hovers over any of the various icons displayed
in the status window (for one each of the six characteristics, another
for alignment, and one for each status condition).  They all already
have text labels below but many of those are abbreviated; the tips can
be more verbose since they don't compete with each for for screen space.

Also fixes "weak" not being centered under the hunger icon.  It /was/
centered but invisible trailing spaces made the visible text be shifted
to the left.

win/Qt/qt_icon.h

@@ -25,7 +25,7 @@ public:
         void setLabel(const QString &, long, const QString &tail=""); // number
         void setLabel(const QString &, long show_value,
                       long comparative_value, const QString &tail="");
-        void setIcon(const QPixmap &);
+        void setIcon(const QPixmap &, const QString &tooltip=NULL);
         virtual void setFont(const QFont &);
         //QString labelText() { return QString(this->label->text()); }