If a container has a new config (e.g. new image), it'll now be removed
right before being re-created.
Before, we were first removing that container among potential orphan
containers, and the container would be re-created later but the downtime
in the middle can be several minutes; since we batch the container
creation.
Now, we separate the cleanup of orphan containers and the ones with new
configs.
The workflow is the following:
1) Remove orphan containers (not in the config anymore, missing Labels,
etc).
Then for each batch of containers:
2) Remove the containers where the config_data has changed.
3) Create the containers that are in the config.
This patch should reduce the downtime of containers that are updated.
Change-Id: I821d674dead4a21b7ac30b47b31b8dd34e0ecc8b
0e24247d2c