explore using sessreg in sdm-session

document (and create scripts) for .ssh/known_hosts configured properly
on terminals, and .ssh/authorized_keys to use the key-based
authentication, as well as the various methods to lock down passwordless 
keys such as command="windowmanager" and from="ip.address.here"
and "X11Forwarding yes" in /etc/ssh/sshd_config

include post-install scripts for sdm-terminal to include lines 
in /etc/inittab, or write an init.d script.

include documentation in sdm-doc, or remove sdm-doc
