Project-specific custom workflow builder

[therecluse26]

Need the ability for users to define a custom set of status columns per-project, and add new statuses. These new statuses should get saved as ProjectItemStatus records, and then the workflow should be saved as JSON in the workflow_statuses field on the Project model.

The UI should be simple and intuitive, allowing the creation and selection of statuses, as well as their order in the workflow. This will probably require a custom component.