Update glance Xen plugin w/ purge props header.
Update glance Xen plugin w/ purge props header.

Update glance XenServer plugin to use X-Glance-Registry-Purge-Props.
Fixes LP Bug #908922.

Change-Id: I4d16fc8fb34e24195f3bc589d42bdbfadaf77398

sebrandon1/nova,cyx1231st/nova,spring-week-topos/nova-week,tudorvio/nova,CiscoSystems/nova,kimjaejoong/nova,LoHChina/nova,affo/nova,bgxavier/nova,devendermishrajio/nova_test_latest,varunarya10/nova_test_latest,edulramirez/nova,Brocade-OpenSource/OpenStack-DNRM-Nova,viggates/nova,savi-dev/nova,Juniper/nova,openstack/nova,ted-gould/nova,SUSE-Cloud/nova,mahak/nova,leilihh/nova,usc-isi/nova,yosshy/nova,vmturbo/nova,JioCloud/nova,usc-isi/extra-specs,rrader/nova-docker-plugin,tangfeixiong/nova,berrange/nova,CEG-FYP-OpenStack/scheduler,sebrandon1/nova,bgxavier/nova,scripnichenko/nova,sridevikoushik31/nova,tealover/nova,sacharya/nova,dstroppa/openstack-smartos-nova-grizzly,gooddata/openstack-nova,hanlind/nova,Triv90/Nova,dims/nova,rickerc/nova_audit,badock/nova,CloudServer/nova,luogangyi/bcec-nova,bigswitch/nova,imsplitbit/nova,adelina-t/nova,bclau/nova,shahar-stratoscale/nova,Francis-Liu/animated-broccoli,yrobla/nova,rahulunair/nova,phenoxim/nova,klmitch/nova,MountainWei/nova,houshengbo/nova_vmware_compute_driver,TieWei/nova,usc-isi/nova,mmnelemane/nova,Juniper/nova,houshengbo/nova_vmware_compute_driver,ruslanloman/nova,SUSE-Cloud/nova,TwinkleChawla/nova,fnordahl/nova,eayunstack/nova,psiwczak/openstack,mikalstill/nova,sridevikoushik31/nova,devoid/nova,raildo/nova,josephsuh/extra-specs,cernops/nova,akash1808/nova_test_latest,apporc/nova,jianghuaw/nova,maheshp/novatest,Metaswitch/calico-nova,DirectXMan12/nova-hacking,devoid/nova,NewpTone/stacklab-nova,rahulunair/nova,DirectXMan12/nova-hacking,dawnpower/nova,rajalokan/nova,mandeepdhami/nova,tealover/nova,NewpTone/stacklab-nova,vmturbo/nova,citrix-openstack-build/nova,mikalstill/nova,JioCloud/nova,plumgrid/plumgrid-nova,alvarolopez/nova,saleemjaveds/https-github.com-openstack-nova,alexandrucoman/vbox-nova-driver,angdraug/nova,sebrandon1/nova,maoy/zknova,bigswitch/nova,barnsnake351/nova,joker946/nova,gspilio/nova,alvarolopez/nova,maheshp/novatest,zzicewind/nova,cernops/nova,eharney/nova,psiwczak/openstack,gooddata/openstack-nova,double12gzh/nova,leilihh/nova,gspilio/nova,petrutlucian94/nova_dev,adelina-t/nova,joker946/nova,yrobla/nova,vmturbo/nova,cyx1231st/nova,Triv90/Nova,sridevikoushik31/nova,eneabio/nova,projectcalico/calico-nova,zzicewind/nova,Stavitsky/nova,badock/nova,belmiromoreira/nova,akash1808/nova,Juniper/nova,thomasem/nova,felixma/nova,petrutlucian94/nova,saleemjaveds/https-github.com-openstack-nova,rickerc/nova_audit,NewpTone/stacklab-nova,noironetworks/nova,virtualopensystems/nova,paulmathews/nova,hanlind/nova,mmnelemane/nova,redhat-openstack/nova,houshengbo/nova_vmware_compute_driver,citrix-openstack-build/nova,blueboxgroup/nova,eharney/nova,j-carpentier/nova,blueboxgroup/nova,luogangyi/bcec-nova,alaski/nova,openstack/nova,KarimAllah/nova,klmitch/nova,Francis-Liu/animated-broccoli,yosshy/nova,eonpatapon/nova,DirectXMan12/nova-hacking,klmitch/nova,petrutlucian94/nova,shahar-stratoscale/nova,Yusuke1987/openstack_template,silenceli/nova,maelnor/nova,devendermishrajio/nova,viggates/nova,akash1808/nova,CEG-FYP-OpenStack/scheduler,raildo/nova,KarimAllah/nova,josephsuh/extra-specs,gooddata/openstack-nova,TwinkleChawla/nova,NoBodyCam/TftpPxeBootBareMetal,eonpatapon/nova,orbitfp7/nova,mandeepdhami/nova,devendermishrajio/nova_test_latest,projectcalico/calico-nova,usc-isi/extra-specs,fajoy/nova,ted-gould/nova,rajalokan/nova,gooddata/openstack-nova,tianweizhang/nova,phenoxim/nova,cernops/nova,zhimin711/nova,akash1808/nova_test_latest,tudorvio/nova,fajoy/nova,tianweizhang/nova,angdraug/nova,ewindisch/nova,jeffrey4l/nova,JianyuWang/nova,j-carpentier/nova,aristanetworks/arista-ovs-nova,ruslanloman/nova,KarimAllah/nova,double12gzh/nova,sridevikoushik31/openstack,affo/nova,sileht/deb-openstack-nova,yatinkumbhare/openstack-nova,virtualopensystems/nova,leilihh/novaha,russellb/nova,TieWei/nova,nikesh-mahalka/nova,jianghuaw/nova,Stavitsky/nova,BeyondTheClouds/nova,mgagne/nova,Tehsmash/nova,edulramirez/nova,isyippee/nova,takeshineshiro/nova,alexandrucoman/vbox-nova-driver,Tehsmash/nova,LoHChina/nova,cloudbase/nova,barnsnake351/nova,petrutlucian94/nova_dev,Brocade-OpenSource/OpenStack-DNRM-Nova,orbitfp7/nova,alaski/nova,cloudbau/nova,shail2810/nova,JianyuWang/nova,bclau/nova,dstroppa/openstack-smartos-nova-grizzly,jianghuaw/nova,savi-dev/nova,JioCloud/nova_test_latest,OpenAcademy-OpenStack/nova-scheduler,tanglei528/nova,iuliat/nova,cloudbau/nova,ntt-sic/nova,Juniper/nova,maheshp/novatest,takeshineshiro/nova,eneabio/nova,NeCTAR-RC/nova,cloudbase/nova,tangfeixiong/nova,tanglei528/nova,CloudServer/nova,rajalokan/nova,cloudbase/nova,shootstar/novatest,maoy/zknova,shail2810/nova,aristanetworks/arista-ovs-nova,qwefi/nova,sileht/deb-openstack-nova,watonyweng/nova,BeyondTheClouds/nova,paulmathews/nova,hanlind/nova,berrange/nova,apporc/nova,NeCTAR-RC/nova,maoy/zknova,sridevikoushik31/openstack,russellb/nova,varunarya10/nova_test_latest,rrader/nova-docker-plugin,jianghuaw/nova,CCI-MOC/nova,whitepages/nova,OpenAcademy-OpenStack/nova-scheduler,fajoy/nova,zaina/nova,Yusuke1987/openstack_template,yatinkumbhare/openstack-nova,russellb/nova,eayunstack/nova,nikesh-mahalka/nova,devendermishrajio/nova,Metaswitch/calico-nova,aristanetworks/arista-ovs-nova,cloudbase/nova-virtualbox,kimjaejoong/nova,whitepages/nova,JioCloud/nova_test_latest,ntt-sic/nova,Yuriy-Leonov/nova,redhat-openstack/nova,usc-isi/nova,NoBodyCam/TftpPxeBootBareMetal,mikalstill/nova,jeffrey4l/nova,CiscoSystems/nova,klmitch/nova,eneabio/nova,noironetworks/nova,felixma/nova,psiwczak/openstack,imsplitbit/nova,mahak/nova,iuliat/nova,vmturbo/nova,savi-dev/nova,shootstar/novatest,silenceli/nova,spring-week-topos/nova-week,dawnpower/nova,mgagne/nova,zaina/nova,watonyweng/nova,maelnor/nova,Yuriy-Leonov/nova,rajalokan/nova,cloudbase/nova-virtualbox,rahulunair/nova,sacharya/nova,paulmathews/nova,Triv90/Nova,isyippee/nova,gspilio/nova,plumgrid/plumgrid-nova,sridevikoushik31/nova,belmiromoreira/nova,BeyondTheClouds/nova,scripnichenko/nova,CCI-MOC/nova,leilihh/novaha,dstroppa/openstack-smartos-nova-grizzly,qwefi/nova,vladikr/nova_drafts,thomasem/nova,yrobla/nova,zhimin711/nova,NoBodyCam/TftpPxeBootBareMetal,MountainWei/nova,fnordahl/nova,josephsuh/extra-specs,openstack/nova,vladikr/nova_drafts,usc-isi/extra-specs,dims/nova,ewindisch/nova,sileht/deb-openstack-nova,mahak/nova,sridevikoushik31/openstack