o make udev_device_new_from_devnum() work with kernels without /sys/dev/
  o enumerate() - add buses and drivers
  o increase ressize buffer

  o lazy init of selinux
  o replace list.h with ccan list.h which is gpl-v2-or-later version
  o get all distros to agree on a default set of rules
  o rework rules to a match-action list, instead of a rules array
  o log warning if the kernel uses CONFIG_SYSFS_DEPRECATED*=y,
    which means that /sys/class/block/ does not exist, but udev
    will depend on it in a future release
  o DEVTYPE for disks is set by the kernel, they will be removed from
    the default rules
  o "udevadm control" commands will only accept the --<command> syntax
  o symlink names to udevadm will no longer be resolved to old command names