Use HTML entities '&lsquo;' and '&rsquo;' instead of straight double quotes

to suit to the SmartyPants looking
Merge branch 'use-html-entities'
Update gems
Merge branch 'update-gems'
Move 'source/stylesheets/_syntax.css.erb' to 'source/stylesheets/vendor/_syntax.css.erb'
Merge branch 'move-vendor-stylesheets'