- xfce-utils removed from Sisyphus
- apt-indicator needs gksu
- add slinux misc packages:
  + pm-utils
  + strace
- image-scripts.d/50services is a script which starts/stop some services

It is actually an effort by glebfm@ to create an experimental
systemd-based Simply Linux LiveCD; I merely reviewed the original
diff, moved kernel related bits to firmware (see preceding commits)
and introduced a dedicated pkglist namespace by creating a directory.