Add bold style for Roboto Slab font.
Only allow comments on articles by default.
Added skip-sitemap flag (fixes #137).
Don't serve draft pages in the XML sitemap.
Merge branch 'master' of git://github.com/gma/nesta

* 'master' of git://github.com/gma/nesta:
  Don't serve draft pages in the XML sitemap.
  Added skip-sitemap flag (fixes #137).
  Only allow comments on articles by default.
  Add bold style for Roboto Slab font.