The compatibility between code and Vxlan Multicast

[jinlings]

Since the default of cloudland is using multicast,but we didn't use it in KVM for Vlan,so no issue while testing, but as the OSA on Z and we are using the share mode, it's using multicast,while we are testing in Z, we added one Ipar, and found it's not working well,we have to add fdb one by one.so we planned to modify code to support multicast to fix compatibility between code and Vxlan Multicast
plan:

1. add fdb for each control
2. setup a Daemon server and make it connect to DB and to search,then to get information,then to communicate with each control