reworked the way we generate hashes. we're using unsalted, base58 hashes now.
moved the way we store our retrieved asset. they go in static/generated. each linky gets a json manifest that sits in that dir.
Merge branch 'develop' of github.com:harvard-lil/linky into develop

Conflicts:
	linky/linky/templates/landing.html
	linky/linky/templates/single-linky.html
	linky/static/css/style.css