waynerobinson/xeroizer — pull request #186 by artspool-dev (2014-12-24 17:28:37+00:00)
Title: Add TrackingCategoryChild record to generic application

When a line item (on a transaction, say) does not have an entry in one of its tracking categories, we must use the `.build` method for `TrackingCategoryChild` to create a new entry, necessitating the `TrackingCategoryChild` model to be available as its own record.