hardcopy support for gl-render and the fltk_backend

[Shai Ayal]

Hi

I attach a changeset which adds postscript output to the fltk backend,
based on the gl-renderer and the gl2ps library
(http://www.geuz.org/gl2ps).
This changeset is relatively big because the gl2ps library is
distributed as 2 files - gl2ps.c and gl2ps.h which need to be included
in the distribution of the project using it. There is no binary
library.
to use :
backend("fltk"); plot(randn(1e3,1)); print("test.eps")

Limitations (which I will try to fix in the future):
1. no support for images
2. only supports the postscript core fonts Helvetica, Times-Roman,
Courier, Symbol, ZapfDingbats (defaults to Helvetica)
3. no support for bold/italic fonts
4. outputs only eps

Shai

gl2ps.gz
Description: GNU Zip compressed data