BZ #1053729 - Foreman controller params should end with _host instead of _ip.

https://bugzilla.redhat.com/show_bug.cgi?id=1053729

Rename controller_pub_ip and controller_priv_ip Foreman Host Group
parameters to more agnostic controller_pub_host or
controller_priv_host-- more agnostic because the user may enter a
hostname or an IP address for those values.