Add a tunable to control how many ARPs are sent.
Add a tunable to control how many ARPs are sent.

This new flag, send_arp_for_ha_count, controls how many
ARPs are sent when binding a floating IP address to an
instance.  Also increased the default number to 3 from 1,
to make this more robust and guarantee other network
devices see them.

Fixes bug 1043796.

Change-Id: Ib9118fcc5334ef4a8c5d7a5e765364e26fea68da

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