Installed the original theme and Disqus

1. Due to my poor knowledge in CSS, it took me long to discover
`sass/custom/_styles.scss' caused the title of each post to be yellow.
I actually installed the "classic" theme again and copied Zaadi's SCSS
files for his Solarized theme for Octopress on GitHub from
https://raw.githubusercontent.com/erikzaadi/solarized-octopress-theme/master/sass/custom/_colors.scss

2. Disqus has been embedded, after "resolving" some problems in the
appearance of the resulting site.  Simply following the description on
https://github.com/erikzaadi/solarized-octopress-theme/issues/1 doesn't
work for me.  Finally, I tested `sass/custom/_colors.scss' bit by bit
and found out a way: add a zero to `$text-color: $base0;'.