Hardening Ubuntu Server

We should look into adding selective system hardening features to Ubuntu Server, and possibly propagate them to the desktop after sufficient testing. The broken-by-default Edgy release provides a good place to throw in security code that can potentially break things, and see exactly what breaks.

Specifically, we should look at incorporating some of the featureset from grsecurity/PaX, such as ASLR, hardened jails, and some of the TCP/IP and socket security features that grsec provides. In addition, PIE and some memory protections should be considered.

Most of these security mechanisms are kernel-based, so we need buyin from our kernel folks.