Save current state to an image file. This file is in
network graphics) format, which can be read by many applications varying from
graphics programs all the way to Web browsers.
This function needs an external library called
libpng. If the library
wasn't available during compilation, this function is unavailable too.
INSTALL for more information about obtaining libpng
and recompiling XaoS.
Available as: menu item, command line option, command