Block device write-verify test.

Block device write-verify test.

This test imports a ram disk device as a physical device into a domU.
The domU initialises the ram disk with data from /dev/urandom and
calculates the md5 checksum of the data (using tee as it is written so as to
avoid reading it back from the device which might potentially mask
problems).
The domU is stopped and the md5 checksum of the data on the device is
calculated by dom0.  The test succeeds if the checksums match, indicating
that all the data written by domU was sucessfully committed to the
device.

This patch also enables tee in BusyBox on the ramdisk and increments the
xm-test version number to 0.8.0.

The patch also installs the block-integrity tests in the default test
set so they get executed.

Signed-off-by: Harry Butterworth <butterwo@uk.ibm.com>
Signed-off-by: Ewan Mellor <ewan@xensource.com>