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
Added robots.txt, with sitemap link
Added stringex and changed to use #to_url for create directory. To don't receive error in url to accented characters.
optimized order of styles and scripts in header
Upgrade ruby version
Merge pull request #408 from dtchepak/category_link_filter

Extract category_link filter from category_generator.rb plugin
updated gems
Merge pull request #537 from joseprio/master

robots.txt generation
Rake task new_post now accepts titles through stdin
This should help resolve issues for zsh users and make it easier to enter titles which freak out Rake's argument processing
removed accidentally added file
Escape github repo descriptions, as they may contain HTML.
Merge pull request #914 from rixth/master

Escape github repo descriptions, as they may contain HTML.
updated ender.js to latest
Whitespace
Merge pull request #936 from richo/cleanup/whitespace

Whitespace