[arch-dev-public] Build machine update

For any Devs/TUs in need of an x86_64 build machine, we're now in business. This machine I have sitting here is not powerful, but it's doing nothing, so we might as well all help out and heat my apartment this winter 8) What I've done is set this machine up to use the new chroot tools from our devtools package, and allow users rights to run the chroot build script. Dan, Jeff, and myself have tested it and it seems to work fine for right now. For people with existing accounts - I will add a motd with instructions soon, so when you see a small HOWTO on login, feel free to go to town. For people who DON'T have an account but still want to build x86_64 packages and don't have a machine, let me know.