drive if it is set.
vinum_lvi: Change line spacing. This is still not right.
Change checks for striped or RAID-5 plexes to a macro 'isstriped',
which now also includes RAID-4.
Change checks for RAID-5 plexes to a macro 'isparity', which now also
includes RAID-4.
vinum_lsi: If the subdisk is initializing or reviving, don't wait a
whole second to check whether it's advancing; wait in increments of 50
ms up to 1 second. This makes for a barely perceptible delay.
Approved-by: jkh