Imported two patches from xen-api.git

commit fa5d8321c27725fad175a2c4d259726e9b63d0ac
Author: Kevin Tower <ktower@towerfamily.org>
Date:   Mon Apr 29 14:10:44 2013 -0700

    Altering get_bridge_name_vswitch() to work correctly with VLANs.
    VLAN-tagged networks/ports are connected to a "fake bridge" device.
    Most ovs-* commands will not work with a fake bridge
    device, so this function needs to return the true parent bridge
    device name, not the fake bridge.  Otherwise, subsequent calls
    in this script to configure port locking via ovs-ofctl will
    (silently) fail, and port locking will not activate.

    Signed-off-by: Kevin Tower <ktower@towerfamily.org>

commit 06c2d0fedc7031c27ad9215a751c404fde1ebb70
Author: George Shuklin <shuklin@selectel.ru>
Date:   Thu Dec 20 17:41:46 2012 +0400

    Fix bridge name selection for vswitch mode in scripts/setup-vif-rules
      -        bridge_name = "xenbr%s" % devid
      +        bridge_name = get_bridge_name_vswitch(vif_name)

      Devid is device number for domU (f.e. vif1.15; 15 - devid) and is definitely NOT a
      xenbr number (xenbr0, xenbr1, etc).

    Signed-off-by: George Shuklin <george.shuklin@gmail.com>

Committed-by: Rob Hoes <rob.hoes@citrix.com>