New Mixin, Updated to Font Awesome 4, Inclusion of Glyphicons and minor tweaks

ADDED .circle() mixin to custom-mixins.less
ADDED app/_/fonts directory for Font Awesome 4.0.0
ADDED Glyphicon Fonts so that you can use either Font Awesome or
Glypicon classes
UPDATED Font Awesome to 4.0.0
UPDATED mobile.less for Bootstrap media queries
REMOVED app/_/font directory