版本：2.0
- https://cdn.bootcdn.net/ajax/libs/font-awesome/2.0/font-awesome-ie7.css
- https://cdn.bootcdn.net/ajax/libs/font-awesome/2.0/font-awesome-ie7.min.css
- https://cdn.bootcdn.net/ajax/libs/font-awesome/2.0/font-awesome.css
- https://cdn.bootcdn.net/ajax/libs/font-awesome/2.0/font-awesome.min.css
- https://cdn.bootcdn.net/ajax/libs/font-awesome/2.0/fontawesome-webfont.svg