Move vendor prefixed properties before the unprefixed ones.
Use the shorthand font property when possible.

Conflicts:
	site/_includes/css/style.css
Be explicit with the `background` property.
Remove units from zero.
Remove duplicate properties.
Add fallback colors.
Add missing vendor prefixed properties.
Simplify selectors.
Change Travis extension
Change Fury extension
Change Gemnasium extension
Switch to 2.1
Remove literal lang name from class, fix #2284

If code language is C classes for comment and language are the same
Update tests

Remove language literal from class in test/test_redcarpet.rb
Switch 2.1 to 2.1.1
Merge pull request #2290 from penibelst/travis-workaround
Update history to reflect merge of #2290 [ci skip]
Merge pull request #2292 from mtcomscxstart/code-class-fix
Update history to reflect merge of #2292 [ci skip]
Set content-type to text/html with utf-8 charset.

Fixes #2289