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/KeyConfigPrefs.cpp

@@ -1211,3 +1211,8 @@ void KeyConfigPrefs::Cancel()
 }
 
 #endif
+
+PrefsPanel *KeyConfigPrefsFactory::Create(wxWindow *parent)
+{
+   return new KeyConfigPrefs(parent);
+}