Allow external ENV setup for conf files
Allow external ENV setup for conf files

In order to keep redstack in synch with devstack, the conf files
referenced within devstack need to be able to be declared externally.

This change allows *_CONF values to be specified, and uses the
original values as defaults.

Change-Id: Ic67f6347b92b05619103a77e9f7ea80a299a6869

avvocatodemarchis/devstack,TwinkleChawla/devstack,bljgaurav/openstack-test,NaokiMiyata/devstack,kplus/devstack-moonshot,pombredanne/devstack,mmasaki/devstack,Mahito/devstack,bigswitch/devstack,noironetworks/devstack,richliu/devstack,bswartz/devstack,rushiagr/devstack,pacinete/devstack,olivierlemasle/devstack,liuquansheng47/devstack,Mahito/devstack,noironetworks/devstack,TwinkleChawla/devstack,mssumanth/devstack,atulpatil301/devstack,group-policy/devstack,varunarya10/devstack,j4/devstack,mssumanth/devstack,herrsechs/devstack,HPCHub/devstack,bq-xiao/devstack,bq-xiao/devstack,varunarya10/devstack,dtroyer/devstack,andrewrothstein/devstack,HPCHub/devstack,openstack-dev/devstack,CloudServer/devstack,NaokiMiyata/devstack,upadhyay-prashant/devstack,dirkmueller/devstack,mc2014/devstack,wenhuizhang/devstack,bigswitch/devstack,neerja28/Devstack_GlusterFS,neerja28/Devstack_GlusterFS,flavio-fernandes/devstack,vishnugonela/devstack,LoHChina/devstack,nawawi/openstack,dtroyer/devstack,j4/devstack,samgoon/devstack,liuquansheng47/devstack,ozamiatin/devstack,bljgaurav/openstack-test,samgoon/devstack,nuxeh/devstack,nawawi/openstack,richliu/devstack,mmasaki/devstack,prithivm/branch01,nuxeh/devstack,pombredanne/devstack,thomasem/devstack,costingalan/devstack,prithivm/branch01,upadhyay-prashant/devstack,bswartz/devstack,pczerkas/devstack,vsham20/devstack,vishnugonela/devstack,LoHChina/devstack,parul24/devstack,ozamiatin/devstack,rushiagr/devstack,mc2014/devstack,kplus/devstack-moonshot,openstack-dev/devstack,avvocatodemarchis/devstack,andrewrothstein/devstack,atulpatil301/devstack,vsham20/devstack,wenhuizhang/devstack,CloudServer/devstack,dirkmueller/devstack,eharney/devstack,eharney/devstack,flavio-fernandes/devstack,thomasem/devstack,herrsechs/devstack,group-policy/devstack,costingalan/devstack,pacinete/devstack,pczerkas/devstack,parul24/devstack,olivierlemasle/devstack