Allow people to specifiy the XENAPI_CONNECTION_URL
Allow people to specifiy the XENAPI_CONNECTION_URL

This is useful when testing host aggregates and not wanting to use
the host local management network

Change-Id: I0d5d13632c74be8d8b8e7de918e7ff28478af9a6

kplus/devstack-moonshot,ewindisch/raspi-devstack,vsham20/devstack,prithivm/branch01,bq-xiao/devstack,samgoon/devstack,avvocatodemarchis/devstack,affo/devstack,neerja28/Devstack_GlusterFS,samgoon/devstack,kplus/devstack-moonshot,vsham20/devstack,bigswitch/devstack,bljgaurav/openstack-test,Yuriy-Leonov/devstack,j4/devstack,bigswitch/devstack,richliu/devstack,NaokiMiyata/devstack,pacinete/devstack,upadhyay-prashant/devstack,deepakselvaraj/devstack,dirkmueller/devstack,varunarya10/devstack,LoHChina/devstack,group-policy/devstack,BSJAIN92/OpenStack,sequenceiq/devstack,promptworks/devstack,yamt/devstack,sc68cal/devstack,ykaneko/devstack,tianweizhang/devstack,nati/devstack_public,nawawi/openstack,upadhyay-prashant/devstack,noironetworks/devstack,pczerkas/devstack,Millnert/contrail-devstack,dirkmueller/devstack,cloudbuilders/devstack,HPCHub/devstack,sc68cal/devstack,pombredanne/devstack,savi-dev/devstack,j4/devstack,bswartz/devstack,herrsechs/devstack,neerja28/Devstack_GlusterFS,nttmcl/devstack_public,bq-xiao/devstack,nuxeh/devstack,mssumanth/devstack,sequenceiq/devstack,jamielennox/devstack,rushiagr/devstack,CiscoSystems/devstack,flavio-fernandes/devstack,flavio-fernandes/devstack,group-policy/devstack,innodee/openstackk,srics/devstack,olivierlemasle/devstack,mmasaki/devstack,thomasem/devstack,ozamiatin/devstack,williamthegrey/devstack,nuxeh/devstack,atulpatil301/devstack,wenhuizhang/devstack,r-mibu/devstack,promptworks/devstack,noironetworks/devstack,TwinkleChawla/devstack,CloudServer/devstack,openstack-dev/devstack,avvocatodemarchis/devstack,LoHChina/devstack,parul24/devstack,shootstar/devstacktest,rushiagr/devstack,richliu/devstack,parul24/devstack,andrewrothstein/devstack,costingalan/devstack,andrewrothstein/devstack,JioCloud/devstack,eharney/devstack,citrix-openstack-build/devstack,nati/devstack_public,mssumanth/devstack,atulpatil301/devstack,vishnugonela/devstack,tianweizhang/devstack,citrix-openstack-build/devstack,wenhuizhang/devstack,Mahito/devstack,virtualopensystems/devstack,ykaneko/devstack,herrsechs/devstack,dtroyer/devstack,bswartz/devstack,eshnil2000/devstack,cloudbuilders/devstack,bljgaurav/openstack-test,ozamiatin/devstack,armando-migliaccio/devstack,HPCHub/devstack,mc2014/devstack,nttmcl/devstack_public,ewindisch/raspi-devstack,TwinkleChawla/devstack,dtroyer/devstack,prithivm/branch01,savi-dev/devstack,sstrato/devstack,liuquansheng47/devstack,eharney/devstack,CloudServer/devstack,pombredanne/devstack,openstack-dev/devstack,thomasem/devstack,pczerkas/devstack,costingalan/devstack,mmasaki/devstack,olivierlemasle/devstack,liuquansheng47/devstack,affo/devstack,Mahito/devstack,inkerra/devstack,pacinete/devstack,BSJAIN92/OpenStack,nawawi/openstack,r-mibu/devstack,vishnugonela/devstack,mc2014/devstack,NaokiMiyata/devstack,varunarya10/devstack,Juniper/devstack