Extract category_link filter from category_generator.rb plugin

Allows category_link to be used as a filter to display a link to
any category.
Raise RuntimeError when gist is unavailable
Convert to integer before comparing. data.code is String
Fix for bottom margin in nested lists.
Add EditorConfig file for Ruby files
Add EditorConfig file for classic theme
Don't display comments link for post excerpts on index page when comments for that post are set to false.
Added robots.txt, with sitemap link
new post of shellscript [ and [[
add google+ and google analytics
new post .bashrc sourced twice
update post 0511
updated to latest version of Sass, fixed deprecation warnings
Fixed “3rd party plugins” wiki page link

Signed-off-by: Brandon Mathis <brandon@imathis.com>
Octopress filters are now limited to html producing templating languages, Fixes #536
Merge pull request #499 from lukekarrys/patch-1

Don't display comments link for post excerpts on index page when comments for that post are set to false
Updated Gemfile
updated plugins to work with latest version of Liquid
Do not strip trailing slash of canonical URLs.

Usually, links for posts are generated with a trailing slash, but
canonical URLs aren't.  Some services (e.g. http://b.hatena.ne.jp/)
are confused with that behavior.

We can fix it by removing canonical URLs, but then anyone may read
a post with /index.html URL and post the URL to some tool or service.
Therefore rel="canonical" seems useful IMHO.

Signed-off-by: OGINO Masanori <masanori.ogino@gmail.com>
Merge pull request #592 from omasanori/fix-rel-canonical

Do not strip trailing slash of canonical URLs.