Add wxUSE_PREFERENCES_EDITOR and the corresponding configure option.

This was somehow forgotten when wxPreferencesEditor was added.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74532 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/preferences.h

@@ -12,6 +12,9 @@
 #define _WX_PREFERENCES_H_
 
 #include "wx/defs.h"
+
+#if wxUSE_PREFERENCES_EDITOR
+
 #include "wx/bitmap.h"
 #include "wx/vector.h"
 
@@ -138,4 +141,6 @@ private:
     wxDECLARE_NO_COPY_CLASS(wxPreferencesEditor);
 };
 
+#endif // wxUSE_PREFERENCES_EDITOR
+
 #endif // _WX_PREFERENCES_H_