Rename directories to the more standard "css", "img" and "js".
Ignore the "_site" folder.
Remove the unused pygment_trac.css.
* add favicon.ico
* add html5shiv, selectivizr and respond.js
* use normalize.css instead of reset
* specify <meta http-equiv="X-UA-Compatible" content="IE=edge">
* remove units from 0 in stylesheet.css
Losslessly compress images.
Remove bg_hr.png.

Use border-bottom instead.
index.md: Add image dimensions.
index.md: reindent for better readability.
dd
sss
stylesheet.css: clean up font properties.