contribution to GiNaC IO "philosophy"

Hi folks. I sketched some very basic stuff around GiNaC::ex output. It could eventually handle all printing, uniformly and FROM ONE PLACE in the source. I am very interested in your comments on it as it serves nothing else; it is not useful yet. Some issues are addressed in the source. It is heavily commented and easy to understand. Have a look at it: http://www.volny.cz/smilauer/ginac_o.cc. Regards. Vaclav Smilauer