[cairo] Cairo library for Ypsilon Scheme

[Eduardo Cavazos]

Hello,

Ypsilon (an implementation of R6RS Scheme) ships with bindings to Cairo. 
The Ypsilon project page is at:

     http://code.google.com/p/ypsilon

I converted the examples in Michael Urman's Cairo tutorial to Ypsilon:

     http://github.com/dharmatech/psilab/tree/master/cairo/examples

Ypsilon's Cairo library API is a direct reflection of the C API. I use 
macros in a few places to make things a little more concise. For example:

    (with-cairo cr
       (scale 120 120)
       (set_line_width 0.1)
       (set_source_rgb 0 0 0)
       (rectangle 0.25 0.25 0.5 0.5)
       (stroke)
       ...)

Ed