Font cleanup

# Global font-size
Changed the font-size property for html/body elements from 16px to 100%. While most browsers default to 16px, this ensures compatibility with brower-based text zoom and user-set defaults. 

# Font smoothing
Restored font smoothing settings to browser defaults. This property only works in one family of browsers and only on the desktop and only on the Mac. Changed from global setting on body element to class based setting. Also, some folks consider this property harmful. (see http://www.usabilitypost.com/2012/11/05/stop-fixing-font-smoothing/)