set up helper method for displaying user avatars
use avatar image helper methods on post show views
use user avatar helper method in reply form
added .noMargin and .noPadding css classes
put a message in place of the comment form no user is logged in
added spinner gif
align comment list container in the center
added helper for spinner and added it to the post show comments
use data attribute instead of rel to get path for loading comments
use data attribute instead of rel when loading comment reply form
added an image preview box to user avatar form
display image preview with js