Support optional 4 arg for nova-dhcpbridge
Support optional 4 arg for nova-dhcpbridge

dnsmasq will call the add, old, and del actions with an optional
4 argument of hostname if the hostname is known. Since we populate
the hostname in the DHCP host file its always passed to us.

Add an optional 4 argument for hostname for the add, old, and del
actions.

Change-Id: I1a6c095324be2424d6c1d469877b254f88fba4aa
Fixes: bug #1103783

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