This is a more sane solution, than ignoring subsequent "change" events.
The only danger is that we could loop, if a lvm scan triggers a broken
md partition, which triggers a broken PV and so on.
Better fix the scanning tools, not to emit change events for devices,
if no action was taken.
Intel BIOS raid is being shifted from dmraid to mdraid because mdraid offers
more features. So if an imsm metadata capable mdadm is present use mdraid
instead of dmraid for isw_raid_member's
This patch also adds code to mdraid_start.sh so that the raidsets
inside the imsm containers get started once udev is done probing
(doing this earlier leads to potentially degraded use of the sets and
an unwanted resync).
Harald Hoyer