Redeploy changed services on stack update

[evanp]

It would be nice if, when I update a stack using docker-cloud stack update, at least the following things happened:

• Any new services were automatically started
• Any services whose definition had changed were automatically redeployed
• Any services that were removed were terminated

[tifayuki]

@evanp Unfortunately, our current API implementation doesn't support that.

When you update the stack:

• Any new service is created but not deployed. You can redeploy the stack or start the service
• Any service whose def has changed is marked as “need to redeploy to apply changes”, Redeploy can cause downtime.
• For security reasons we don’t terminate services when they are removed from a stack

You have to redeploy the stack and terminate the removed services manually afterwards. If you don't like the downtime caused by the redeployment, you can manually start the newly created service and redeploy the services we marked “need to redeploy to apply changes”.