ofagent: merge br-tun into br-int

Highlights:
- Deprecate br-tun.
- Reduce the use of OFPP_NORMAL action.  Use mac address info
  obtained from get_device_details and l2-pop to reduce flooding.
- Use OpenFlow metadata instead of "internal" VLANs.
  Now tenant networks are VLAN transparent.

Implements: blueprint ofagent-port-monitor
Implements: blueprint ofagent-merge-bridges
Change-Id: I21ee1c6d141863182b487e10c7bfe911b1a472ab
ofagent: Enable local arp responder for local VMs

Because ofagent handles packet-in and perform packet-out anyway,
just make it respond arp request for local VMs.

Related: blueprint ofagent-l2pop
Related: blueprint ofagent-merge-bridges
Change-Id: I606a238d8c2021ed908fbd89d3488768497f57c5
l2pop: Allow network types overridable

Currenly "tunnel_types" is used for two different purposes; l2pop and
check_segment_for_agent.  This commit introduces a new agent
configuration "l2pop_network_types" to allow overriding the former.

This will be used by ofagent, which wants l2pop info for TYPE_VLAN
as well.

Related: blueprint ofagent-l2pop
Related: blueprint ofagent-merge-bridges
Change-Id: Ia83a94b6661aa36afa8bfeb073101171ffde62a9
ofagent: Local arp responder for VLAN

Implement local arp responder for non-tunnel network types.
Enable it for VLAN by requesting l2pop for VLAN.

Related: blueprint ofagent-l2pop
Related: blueprint ofagent-merge-bridges
Change-Id: I2f200a1ae2bd769ea1f83fe65e58e82325ed92b0
Remove unneeded device_owner field from l2pop tuple

The DVR development added this device_owner to the middle of this
tuple during early development because it was thought to be needed.
Over the course of development, it was found to be unnecessary and
much of the code that read it from this value was removed or
obsoleted.  That job went unfinished and so this commit completes it.
This essentially restores the code to what it was before and fixes the
regression that was caused.

Change-Id: Ia901f925883b53e9880dd25688e16e0ffe402bf4
Partial-bug: #1352801