Extract orm specifics

rework of PR #454

ORM specifics except Active Record has extracted to [doorkeeper_bundle](https://github.com/jasl/doorkeeper_bundle) (not push to rubygems yet)
Unused block argument - `routes`. If it's necessary, use `_` or `_routes` as an argument name to indicate that it won't be used. Also consider using a proc without arguments instead of a lambda if you want it to accept any arguments but don't care about them.