A tweak to the S5 CSS stylesheets. Hiding SVG is a little tricky...
More tweaks to the supplied S5 themes. Fixed a minor regression in the non-Math Markdown engine.
Corrected some small problems in the CSS.
Added support for S5 Themes. Themes are stored in the public/s5/themes/ directory. 6 themes are included: default, nautilus, blue, flower, i18n, pixel.