Move avatar function to helpers
Default avatars
Large & small default avatar support
GAHAHAHAH

I want to kick gravatar in the nuts (lack of svg support and all sorts of other things), so instead we're using a hot combo of gravatar with our default image hosting service (since transparent + hue effect = non transparent image), and the large image has the scripted SVG object behind a gravatar that defaults to transparent.

BASICALLY CONFUNKSION.
Add a sane default
Merge pull request #1829 from jsbin/feature/default-avatar

Default avatar