This patch adds a new CLI command 'container upgrade foo', where 'foo'
is the name of the container. If more than one container use the same
image, multiple upgrades must be done because a container runs not on
the 'image:tag' but on the hash of the 'image:tag' it was created from.
Rename "done" queue to "active", since we want to recreate an active
container after fetching an updated base image.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>