Multi controller support

In order to achieve high availability for the SDN controller this blue print add to the DragonFlow OpenFlow controller support for multiple controller.
The blueprint intend to support two controller mode
1)OpenFlow Active Passive (Master Slave )
Each OVS will have one controller Master and second define as Slave, due to the stateless nature of the L3 SDN application (dragonFlow) Slave controller of one compute node could be Master for a second compute node.
By doing that we can still distribute the load over the multiple controller even for OpenFlow master slave controller mode
2) OpenFlow Equal
Each OVS will have multiple controller define as equal, the controller will synchronize between them self who handle the first packet