Tail stdout/stderr on running jobs page

[LincolnBryant]

It would be very convenient to follow the stdout and stderr of a job from the kotta job page. Typically I know where a job may potentially hang, so if it's stuck I'd like to be able to cancel it.

[yadudoc]

Task breakdown.

• Add radio button to job submit form that enables log stream.
• Add log stream functionality to worker
• Show log stream when job is running but s3 url once completed in the jobs page