Change password for cloud servers if instance already exists

@techhat, please double check that I am using these functions correctly.

The idea is... if the instance already exists, and you don't have ssh_key_file specified, it will just use the api to change the root password using the salt.utils.pycrypto's secure_password that I made at some point in the past, so that it can ssh to the root user and then bootstrap the servers.

Thanks!
Daniel