add checksums to udp independent of /dev/vhost-net.

In newer kernel versions, the network devices added for lxc containers
do not get checksums added.  The result is the same as previously
occurred when vhost-net became prevalent in kvm guests.

Software that expects the checksums on packets will ignore them.  One example
of such software is udhcpc in cirros.  Without this change, cirros containers
in 3.13 kernels (Ubuntu 14.04) will fail to acquire an address via dhcp.

Closes-Bug: #1335193
Change-Id: Iba305fb7f8236955ca732e467db9e424535be93d
Virt: fix typo (flavour should be flavor)

Commit 0c74df4962f256d9bc17b57c22ea45ece94e2f1a added support
which used the word flavour. Flavour is the preferred
spelling throughout the rest of the English-speaking world, but
flavor is preferrred spelling for OpenStack.

TrivialFix

Change-Id: I5fb3dd1601324c6be4f4d159166f5cacbec16a7e
libvirt: add migrateToURI2 method to fakelibvirt

With the merge of

  commit ea7da5152cdca7ba674e2137c3899909995e2287
  Author: Solly Ross <sross@redhat.com>
  Date:   Tue Feb 4 14:27:51 2014 -0500

    Change listen address on libvirt live-migration

the libvirt driver uses migrateToURI2 instead of
migrateToURI. The fakelibvirt class did not define
this method so it was unable to be mocked out.

Change-Id: I74c28119c979e511cece6b839e25a40197b0e5d9
Closes-bug: 1342498
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
shelve doesn't work on nova-cells environment

The compute_api shelve/unshelve methods expect an Instance object,
but cell is still passing the sqlalchemy form.
So adding shelve/unshelve to the list of methods that will receive an
Instance object when using nova-cell.

When shelving instance with nova-cell environment,
instance object needs to contain 'metadata' and 'info_cache'.
So fetching the same from databse and adding it to
instance object before calling shelve/unshelve methods.

Closes-Bug: #1338451
Change-Id: Ia31b33c9a1d347f15d3e0a67fa31ef6b25a7407a
Merge "Virt: fix typo (flavour should be flavor)"
Merge "libvirt: add migrateToURI2 method to fakelibvirt"
Merge "add checksums to udp independent of /dev/vhost-net."
Merge "shelve doesn't work on nova-cells environment"