Use bootstrap responsive features
* add media query for width on computers
* change .row to .row-fluid for nag bar smartness
Move typography & pretty icon CSS into sep sheets
Simplify CSS for feature boxes
* move box-specific styles onto .feature class
* rename feature-list to features-grid for more semantic meaning
* remove absolute positioning from event buttons
* change box width from % to px
* remove duplicate CSS
* update HAML to reflect updated Sass