Removal of outdated Controller parts

[mkraposhin]

Currently, controller contains several outdated (sometimes even broken) parts:

• bfd application (controller/src/bfd), even doesn't contain needed include files;
• bgp daemon (controller/src/bgp/daemon), the purpose of the program is unclear;
• OVS ToR agent (controller/src/vnsw/agent/ovs_for_tor_agent), most likely even not used today by anyone in the world;
• VxLAN agent (controller/src/vnsw/agent/vxlan_agent/linux) looks like contains wrong linker settings, i.e., most likely not used today;
• etcd client (src/contrail-common/config-client-mgr/config_etcd_client.cc) seems to be unused nowadays.

[mkraposhin]

All these programs are not included in contrail.spec file