nixos-install: Fix running it after again the activation script
mkpasswd: Add to channel
Don't create /media

It's obsolete - udisks2 uses /run/media/<username>.
test-driver: Set context to include machines created by createMachine
NixOS ISO: Don't use a unionfs for /

We don't need a unionfs on /, we only need a tmpfs.
Don't kill unionfs-fuse during shutdown

Killing the daemon backing /nix/store prevents a clean shutdown.  See
http://www.freedesktop.org/wiki/Software/systemd/RootStorageDaemons/
Installer test: Get rid of a warning
Enable the xf86-video-modesetting driver
Installer test: Don't wait for dhcpcd if we don't have a network