Updates to tuxlite_zf theme.

Numerous styling fixes.

1.  Change header and site name colors
2.  Fix heading sizes for pages and archives
3.  Change navigation link color
4.  Fix syntax highlighting. Now using solarized theme
5.  Fix HTML lists using list-style-position
6.  Increased spacing between posts
7.  Update zurb foundation CSS, JS files

New screenshot attached

![Screenshot](https://raw.github.com/mins/pelican-themes/master/tuxlite_zf/Screenshot.png)