partition offsets. If user requests specific alignment and
provider's stripesize is not zero, then use a least common multiple
from the stripesize and user specified value.
Also fix "gpart resize" implementation: do not try to align the partition
size, because the start offset may be not aligned. Instead align the
end offset and then calculate size. Also use stripesize and stripeoffset
for "gpart resize" command.
401a1d9956