Add disqus comments

Enable disqus comments by adding DISQUS_SITENAME to to pelicanconf.py.
Minor changes
Merge pull request #7 from kkingori/master

Add Disqus comments for posts.
templates/base.html: Add logic to include Google Analytics
Merge pull request #9 from alanorth/analytics

templates/base.html: Add logic to include Google Analytics
Use github-style code highlighting

From: https://github.com/aahan/pygments-github-style/blob/master/github.css
Merge pull request #10 from alanorth/pygments-style

Use github-style code highlighting