Table-driven construction of Prefs dialog. A factory for each kind of panel...

... and maybe a future plug-in protocol to break compilation dependency on
all of the PrefsPanel subclasses.

src/prefs/WarningsPrefs.h

@@ -33,4 +33,9 @@ class WarningsPrefs :public PrefsPanel
    void PopulateOrExchange(ShuttleGui & S);
 };
 
+class WarningsPrefsFactory : public PrefsPanelFactory
+{
+public:
+   virtual PrefsPanel *Create(wxWindow *parent);
+};
 #endif