SSH based pam authentication agent for LTSP

In order to move ldm away from screen scraping, and towards a proper pam compliant login mechanism, we need a pam module that authenticates via an ssh login, and creates a command socket.

Persistent pluggable home directories for LTSP users for Ubuntu

Rather than store their home directories up on a server, some users would like to plug in flash media, and run off their memory stick. This currently works on the live CD. We should look at getting this to work for LTSP thin clients as well.