xenapi: display IP and DevStack result on console
xenapi: display IP and DevStack result on console

The devstack setup service can update /etc/issue, displaying the status
of the installation and the VM's management IP. With this change, after
the devstack service finsihed, the login prompt will look like this:

OpenStack VM - Installed by DevStack
  Management IP:   10.219.3.108
  Devstack run:    SUCCEEDED

DevStackOSDomU login:

This helps people to log in to their system.

Change-Id: Idd6bbd5faf9ced5618cd3e95191bfc3b89473fa2

costingalan/devstack,affo/devstack,ozamiatin/devstack,tianweizhang/devstack,bigswitch/devstack,bigswitch/devstack,flavio-fernandes/devstack,bq-xiao/devstack,TwinkleChawla/devstack,dirkmueller/devstack,virtualopensystems/devstack,mc2014/devstack,innodee/openstackk,wenhuizhang/devstack,liuquansheng47/devstack,liuquansheng47/devstack,eharney/devstack,avvocatodemarchis/devstack,j4/devstack,mssumanth/devstack,mssumanth/devstack,thomasem/devstack,Mahito/devstack,mc2014/devstack,dirkmueller/devstack,jamielennox/devstack,richliu/devstack,affo/devstack,vsham20/devstack,eharney/devstack,pombredanne/devstack,mmasaki/devstack,pombredanne/devstack,varunarya10/devstack,vsham20/devstack,neerja28/Devstack_GlusterFS,rushiagr/devstack,HPCHub/devstack,eshnil2000/devstack,tianweizhang/devstack,noironetworks/devstack,wenhuizhang/devstack,BSJAIN92/OpenStack,nawawi/openstack,noironetworks/devstack,Millnert/contrail-devstack,kplus/devstack-moonshot,parul24/devstack,dtroyer/devstack,nuxeh/devstack,sc68cal/devstack,BSJAIN92/OpenStack,pczerkas/devstack,upadhyay-prashant/devstack,LoHChina/devstack,herrsechs/devstack,samgoon/devstack,ozamiatin/devstack,atulpatil301/devstack,pczerkas/devstack,Juniper/devstack,bswartz/devstack,bq-xiao/devstack,neerja28/Devstack_GlusterFS,prithivm/branch01,nawawi/openstack,samgoon/devstack,upadhyay-prashant/devstack,bljgaurav/openstack-test,rushiagr/devstack,williamthegrey/devstack,vishnugonela/devstack,bswartz/devstack,j4/devstack,JioCloud/devstack,sc68cal/devstack,NaokiMiyata/devstack,atulpatil301/devstack,NaokiMiyata/devstack,pacinete/devstack,srics/devstack,parul24/devstack,herrsechs/devstack,pacinete/devstack,richliu/devstack,thomasem/devstack,promptworks/devstack,openstack-dev/devstack,vishnugonela/devstack,costingalan/devstack,openstack-dev/devstack,dtroyer/devstack,olivierlemasle/devstack,varunarya10/devstack,yamt/devstack,Mahito/devstack,sequenceiq/devstack,nuxeh/devstack,bljgaurav/openstack-test,mmasaki/devstack,LoHChina/devstack,TwinkleChawla/devstack,andrewrothstein/devstack,group-policy/devstack,group-policy/devstack,kplus/devstack-moonshot,flavio-fernandes/devstack,HPCHub/devstack,prithivm/branch01,olivierlemasle/devstack,andrewrothstein/devstack,CloudServer/devstack,CloudServer/devstack,sequenceiq/devstack,avvocatodemarchis/devstack,promptworks/devstack