[Results] Flat results are always unique (no multiple occurrences of the same id).
[Gemfile] Remove Core. Add Sequel, PG.
[Load] Models.
[Models] Add pod/version/commit models and necessary search methods in Pod.
For now, comment obsolete code.
Remove Core code.
[Pods] Rename sets to pods.
[Pods] Rename #pods -> #each.
Comment WrappedSet specs.
[Gemfile] Use latest Picky.
[Move to DB] Start fixing various specs.
Add DB dump for specs.
Test using the first 1000 pods.