Merge branch 'devel-2.7'

* devel-2.7:
  NEWS: Fix the fix in commit 82b6f9ac
  NEWS: Fix release date for 2.7.0 beta1
  Minor fixes regarding nic.network change
  Fix issue 378
  NEWS: Mention multi-alloc and fix typo
  Add cfgupgrade for changing nic.network to uuid
  Remove useless code in backend for network hooks
  Show network name and not uuid in instance info
  Add IQ_NETWORKS in query tests
  Implement network locking in Instance queries
  Changes in query to support nic.network as uuid
  Modify query LUs to supoprt nic.network as uuid
  Add GetInstanceNetworks() config method
  cmdlib changes to support nic.network as uuid
  Make network config methods take uuid as argument
  Document possible hypervisor bug in serial_console
  Update man pages wrt ExtStorage

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>