CA-97364: Ignore exception during domain.destroy

Signed-off-by: Jon Ludlam <jonathan.ludlam@eu.citrix.com>
CA-97364: dbsync destory migrated remnants

Signed-off-by: Jon Ludlam <jonathan.ludlam@eu.citrix.com>
CA-97364: Killall xenguest during XAPI start

Signed-off-by: Jon Ludlam <jonathan.ludlam@eu.citrix.com>
Merge pull request #1337 from zli/xenserver/obelix/HFX-668

Obelix/HFX-668