Stop delete polling after status == DELETED.

A rackspace server can be in status DELETED for some minutes
until a 404 is raised. This change speeds the deletion of a stack
by considering the resource deleted as soon as the status changes
to DELETED.

Change-Id: Id81d3099ef6b41b374973074b065b20c2acc9667
Call cfn-create-aws-symlinks in rackspace servers.

This will also be required for arch, gentoo and opensuse
when the pip install prefix is known.

Change-Id: If789c603c3677c88d30e018cf6ca71925bad9511