Fixes #2025

I forgot to validate the volumes field!

Fixes race on StreamFramer Destroy

Improve parsing of job struct

Log when lookup in docker.auth.config fails

Make container exist errors non-retriable

Use net.JoinHostPort instead of fmt.Sprintf

Using fmt.Sprintf breaks IPv6 addresses.

This change makes it so that the task runner does not retry container
exists errors and also a sleep is added on the local retry.

(bug)Fix error message. Pass on template args

Fix typo in telemetry documentation.

Fixes #2008

This PR:
* Fixes a race in which StreamFramer could panic while closing.
* Simplifies the logic of the StreamFramer
* Removes a potentially leaked goroutine

Make downloads great again

Update encryption docs