Expose per-user and per-workflow GET-job endpoints?

[tcompa]

I guess the most reasonable URLs are

• GET /api/v1/project/7/workflow/3/job/ -> all jobs of a given workflow (TODO)
• GET /api/v1/project/7/job/3 -> one job of the current user
• GET /api/v1/project/7/job/ -> all jobs of a given workflow
• GET /api/v1/project/job/ -> all jobs of the current user (TODO)