Let's put main functionality into params version of virDomainMigrateUnmanaged
as a preparation step for merging it with virDomainMigratePeer2PeerParams.
virDomainMigrateUnmanaged then does nothing more then just adapting arguments.
Signed-off-by: NNikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>