Mathed dependency on libXpm

[Lars Gullik Bjønnes]

It looks like math_symbols.C contains one line that is the only place
where we use a function from libXpm that is not in XForms:

math_symbols.C:531:     XpmCreateDataFromImage(fl_display, &data, sbima, sbima, 0);

Can this be done in a way where we use XForms functions or Xlib
functions, so that we can remove the dependency on libXpm?

Alejandro?

        Lgb