Initial attempt at styles

This commit includes an initial fork of the default Pelican style which
replaces most of the templates and all of the CSS with the Graphite
style I've already written for Sphinx and Docutils.
Updates to theme and added second post

This commit should complete the theme changes required for the main
pages (i.e. index page and article pages). I'm sure there will be plenty
of updates required to get the whole lot looking good, however.