application reorg

- move sinatra app into app/
- create config.ru and move all config stuff into it
replace dm-redis with rethinkdb
fix callback and implement take
update documentation and .env
automatically update pocket
start rethink & shotgun for development
add dumb wireframe to README
remove redis cruft from Rakefile
add pagination to story stream
initial implementation of fibit

also I finally learned how to use omniauth which really just simplifies
everything about working with oauth and I'm quite pleased about it. I
feel like now that I understand, it will be dead simple to import a few
more sources and start feeling like I've made some progress.