src/udev: bring up to date with upstream.

These commits were authored by

    Zbigniew Jędrzejewski-Szmek
    Tom Gundersen
    Kay Sievers
    Lennart Poettering
    Shawn Landden
    Daniel Buch
    Martin Pitt
    Karel Zak
    Yang Zhiyong

Note: udev_builtin_net_setup_link has *not* been imported.  Also
still missing from udev-builtin is udev_builtin_uaccess.

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>