Add yajl-ruby gem to work around zeus problems.

See http://stackoverflow.com/questions/16543693/you-are-using-an-old-or-stdlib-version-of-json-gem
Name app
Add models
upgrade rake
Add seed data
Specify different types of addresses

using single-table inheritance
Get Rack::MiniProfiler widget out of the way
Display developers in simple list
Show addresses for each developer
Solve n+1 query problem
Add sorting options
Don't Repeat Yourself
Add 'starting_with' scope
Substring at db; avoid initializing AR objects
Use left join to preload child records