Xen handle domain shutdown
Xen handle domain shutdown

Update Xen backend to properly recognize when a domain has been
shutdown by the user and to properly cleanup a shutdown domain when
Ganeti requests Xen to stop this domain.

Partial cherry-pick from 9d22cc90609e3ee8f0f2b34b793a3daced3c0e61

Signed-off-by: Jose A. Lopes <0fb9c4f8511df4ec2ae28af879e9d462f6218a2c@google.com>
Reviewed-by: Michele Tartara <05f7077a2c6cbbdc4af4ba42e3ef89a0df846179@google.com>

ganeti/ganeti,yiannist/ganeti,ganeti-github-testing/ganeti-test-1,grnet/snf-ganeti,andir/ganeti,yiannist/ganeti,apyrgio/snf-ganeti,grnet/snf-ganeti,apyrgio/ganeti,leshchevds/ganeti,bitemyapp/ganeti,apyrgio/snf-ganeti,mbakke/ganeti,bitemyapp/ganeti,ganeti/ganeti,andir/ganeti,leshchevds/ganeti,andir/ganeti,dimara/ganeti,apyrgio/ganeti,mbakke/ganeti,mbakke/ganeti,onponomarev/ganeti,ganeti-github-testing/ganeti-test-1,ganeti/ganeti,onponomarev/ganeti,dimara/ganeti,leshchevds/ganeti,yiannist/ganeti