packages: re-add cups printing services to default install
packages: DE: switch from tint2/openbox/compton -> xfce4-panel/xfwm4
 * remove obsolete autostart entries
 * remove compton, openbox and tint2 from default install
 * use xfwm4 and xfce4-panel instead
 * update xfce4-session settings to start xfwm4 and xfce4-panel
 * reorder package lists
doc: update packages doc and alternatives, comment ufw rules
launchers: remove obsolete launchers
packages: update adv-network-tools.list.chroot.disabled
packages: remove unison from default install