Bug#543163: lvm2: Please don't depend on udev

[Alasdair G Kergon]

Upstream lvm2/dm continues to support systems that do not use udev and
we have no plans to change that at the moment.  Even on a system with udev
installed, if it's not running, lvm2 is supposed to detect that and still
work like it did before.  (There are also manual options - see udev_sync in
lvm.conf and --noudevsync.)

But the focus upstream and in the major distributions is towards even tighter
integration of lvm2 and udev.

Alasdair