Only use the create_before_destroy-hook in launch configurations. The autoscaling group must not use the create_before_destroy-hook, because it can be updated (and not destroyed + re-created). Using the create_before_destroy-hook in autoscaling group also leads to unwanted cyclic dependencies.
See #2911.
This adds a `name_prefix` option to `aws_launch_configuration` resources.
When specified, it is used instead of `terraform-` as the prefix for the
launch configuration. It conflicts with `name`, so existing
functionality is unchanged. `name` still sets the name explicitly.
Added an acceptance test, and updated the site documentation.
Seth Vargo