Ability to specify keystone v3 in nova.conf for neutron
Ability to specify keystone v3 in nova.conf for neutron

As part of moving components to use keystone v3, this review
allows nova.conf's [neutron] section to switch to using the
auth_plugin in keystoneclient for talking to keystone /v3 API

Change-Id: I42502bff147534199096fb581630b8559f311963

mc2014/devstack,varunarya10/devstack,dtroyer/devstack,TwinkleChawla/devstack,dirkmueller/devstack,costingalan/devstack,pczerkas/devstack,openstack-dev/devstack,avvocatodemarchis/devstack,costingalan/devstack,TwinkleChawla/devstack,prithivm/branch01,noironetworks/devstack,pombredanne/devstack,samgoon/devstack,nawawi/openstack,atulpatil301/devstack,richliu/devstack,avvocatodemarchis/devstack,group-policy/devstack,bigswitch/devstack,mssumanth/devstack,openstack-dev/devstack,bswartz/devstack,parul24/devstack,vsham20/devstack,varunarya10/devstack,parul24/devstack,pczerkas/devstack,prithivm/branch01,dirkmueller/devstack,dtroyer/devstack,atulpatil301/devstack,thomasem/devstack,olivierlemasle/devstack,samgoon/devstack,group-policy/devstack,nawawi/openstack,Mahito/devstack,noironetworks/devstack,ozamiatin/devstack,thomasem/devstack,eharney/devstack,bswartz/devstack,ozamiatin/devstack,pombredanne/devstack,Mahito/devstack,richliu/devstack,eharney/devstack,olivierlemasle/devstack,mc2014/devstack,mssumanth/devstack,bigswitch/devstack,vsham20/devstack