Use codex to generate SQL for selecting torrent by ID.
Remove additional debugging info when reading `.torrent` file from a multipart form.
torrent model uses `codex` to build SQL queries.

* Formats []byte as string b/c library has no visitor for []byte. -- This is PostgreSQL specific and will break on other DBs.
* Tagged struct because I plan to build or find a light-ORM like tool for the simple CRUD/dynamic finders.
* For now struct-tags aren't used, they're just there for future reflection, and documentation purposes.
Merge branch 'feature/db-torrents' into develop