Makes unfiltering work by toggling the class.

Fixes #341
Closes #365

Reviewed-by: Stef Walter <stefw@redhat.com>
agent: Dig out detailed docker error messages

The HTTP status of a lot of Docker failures is just "Internal Server
Error". It also has a textual failure in the HTTP body. We were just
discarding this as it wasn't JSON.

Instead we now grab text in the body of the HTTP message when we
get a failure with a Content-Type of text/plain (or no type).

Reviewed-by: Patrick Uiterwijk <puiterwijk@redhat.com>
Return to image/container overview after run

Closes #336

Signed-off-by: Stef Walter <stefw@redhat.com>
 * Whitespace fixes
Show image tags in Run Image dialog.

Fixes #337
Sync jargon and only show first repotag