CA-92550: Update xenstore permissions on /vm/<uuid> tree to reflect the new domain ID when a domain is rebooted or migrated to localhost.

Signed-off-by: Euan Harris <euan.harris@citrix.com>
Merge pull request #1737 from johnelse/ca-92550-xs64bit

CA-92550: Update xenstore permissions on /vm/<uuid> tree to reflect the new domain ID when a domain is rebooted or migrated to localhost.