Make `jobq [submit|stop|list|logs]` aware of project concept

[AdrianoKF]

Goals:

• Default is to operate on a single project
• list can also support --all-projects/-A to list from all projects the user can see

Additional tasks:

• Migrate existing commands to jobq job subcommand to prevent name clashes

Implementation considerations:

• Jobs are conceptually a subresource of projects, so it is probably sensible to make /projects/<id>/jobs the main API to interact with jobs (at least for submitting new ones). TODO: Examine what the Zalando RESTful API guide has to say on this.