Merge pull request #8 from loladiro/master

Make Compose use Cairo package
Fix a fontconfig call.
Well defined z-orders among canvases, and inheriting parent's coordinate system.
Hash embedded svg objects so they aren't included multiple times.
Fix z-ordering. Add a catchall SVGAttribute property.
When no file is given to SVG, show the graphic in a browser window.
Disable the cairo backend for now.
Fix link to Gadfly in README.md.
Merge pull request #9 from ianfiske/patch-1

Fix link to Gadfly in README.md.
fix the embedded Sierpinski gasket
Merge pull request #10 from StefanKarpinski/patch-1

fix the embedded Sierpinski gasket
Rearrange a little. Switch all ccalls to the new style.
Functions to simulate colorblindness.
Work on color palette optimization.
Add missing show.html.
Better distinguishable color optimization.
Add .htm suffix to temp files before passing to browser
Merge pull request #12 from microtherion/add-htm-suffix

Add .htm suffix to temp files before passing to browser
Add test for colordiff. Complete distinguishable_colors
Cairo backend fixes.