[Stk] avoid stdout prints

[Norman Casagrande]

Hi Gary

>If I had done this correctly, you could then go into Stk.cpp and change 
>the behavior so that "status" messages do not print unless in debug mode 
>(or not at all).  I'll try to make that more consistent in the next release.

Well, I'd rather not modify the original library, because every time there 
is an update I need to change it over again. It would be better to have 
something like a static method to set up the output stream:
   std::ostringstream errorString_;
so that the user can decide where to send it.

Thank you for your help!


Norman Casagrande
LISA Lab
Université de Montréal