ssh_host_keys

[Mike McGrath]

We are now distributing an ssh_known_hosts file to all of our servers.
This means that you can blow away your ~/.ssh/known_hosts file.  When
servers get rebuilt either replace it with the old ssh key, or update the
puppet/modules/ssh/files/ssh_known_hosts file with the new key.

I've not actually used global ssh_known_hosts before, I wouldn't be
surprised if it causes issues in some of our scripts that might have a
conflicting ~/.ssh/known_hosts.  Lets keep our eyes open.

	-Mike