move icon font declaration into new stylus file
add lato font to font stylsheet
remove unused images
updates homepage stylus
remove pointless subpixel dimension properties
add variables for font-weights
small updates to nav mascot svg
apply new font styles
remove errant reference to nonexistent image in homepage mascot svg
use colons consistently in stylus
Merge branch 'master' into improve_typography

* master:
  remove errant reference to nonexistent image in homepage mascot svg
  small updates to nav mascot svg
  remove pointless subpixel dimension properties
  remove unused images