Two improvements for md

1/ Don't install the udev rules file 64-md-raid.rules.
  It has been renamed to 2 different files, and the mdadm
  package installs it now.

2/ Run "mdadm -IRs" at half-time when waiting for the root
  device to appear.
  This will start any newly-degraded array (weren't degraded when
  machine was shut down).

Signed-off-by: NeilBrown <neilb@suse.de>