iotests: run the persistent dirty bitmap test on parallels

parallels stores persistent dirty bitmaps now, so test 165 applies to it
as well. The bitmap name is the only format specific bit: parallels
keeps it as the UUID identifying the bitmap in the image, so a name like
'bitmap0' is rejected on store.

test_reopen_rw is skipped, as parallels has no bdrv_reopen_prepare() and
blockdev-reopen fails with "does not support reopening files". Skipped
cases do not show up in the reference output, so 165.out stays as it is.

test_persistent covers what the series adds: it dirties the bitmap,
records its hash, restarts the VM twice and compares the hash again,
which passes only if the bitmap survives both the store on inactivation
and the load on open.

Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>