Update application.css.

Clean up fonts; there's no need to specify all of them in each selector since they are inherited.
Also, use the shorthand font property.
Update application.css.

* add missing fallback color
* add missing vendor prefixed property for Opera
Get rid of the unicode symbol from selector's name and use class instead of id.
Rename clearfix class.
Update qTip custom selectors.

* group common properties together
* get rid of the useless `!important` declarations
Move qTip inclusion at the top so that it's clear.