add ssh usernames to try
updated public_ips example

this is updated to the correct name for the current version of salt-cloud.
Merge pull request #207 from ydavid365/patch-1

updated public_ips example
better public_ips and private_ips documentation

fixed public_ips examples in both places.
Merge pull request #208 from ydavid365/patch-1

better public_ips and private_ips documentation