[XForms] Where to add entry for forms.h

[Jeff]

Angus, or anbody,

Where do I add the line:
FL_CLIENT_CALLBACK client_callback;
 so it appears in the forms structuer. I thnk it would go into Basic.h. 
But do I also need to adjust the line
    int reserved[10];           /* future use              */

to include the size of the new client_callback enty in struct FL_FORM in 
Basic.h

I also guess the header declaration
FL_EXPORT FL_CLIENT_CALLBACK fl_register_client_callback(
                FL_FORM *form,
                FL_CLIENT_CALLBACK rcb
                );

Would also go into Basic.h.

I want to finally submit this patch.

Jeff