Support new encap type for native ip-fabric forwarding

[Nischal Sheth]

As part of ip-fabric forwarding support, CN needs the ability to indicate
in the L3VPN route for an endpoint that the endpoint has an IP address
from the underlay and hence is capable of native forwarding i.e. without
MPLS encapsulation. Proposal is to signal this by advertising a "native"
encapsulation in XMPP and BGP. Note that "native" encapsulation can and
will be advertised along with other encapsulations like udp and gre i.e.
it need not be exclusive.

The vRouter can determine whether to use overlay or native encapsulation
based on the properties of the source VN and encapsulations signaled in
the destination route. Conceptually, we can think of native encapsulation
as having the highest priority.

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/34044
Submitter: Nischal Sheth (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/34044
Committed: http://github.com/Juniper/contrail-controller/commit/1e130f4b61d14aa56715ad5eee9b7cd0d8e0d9b4
Submitter: Zuul (<email address hidden>)
Branch: master

commit 1e130f4b61d14aa56715ad5eee9b7cd0d8e0d9b4
Author: Nischal Sheth <email address hidden>
Date: Wed Jul 26 12:28:38 2017 -0700

Add support for native encapsulation type

Change-Id: Idd1a3b139c9ea9e3a42bba5474c69f32537b1d6b
Closes-Bug: 1706726

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/36476
Submitter: Nischal Sheth (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/36477
Submitter: Nischal Sheth (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/36477
Committed: http://github.com/Juniper/contrail-controller/commit/514af74b823f65f9a985a85688863dcdbb81db14
Submitter: Zuul (<email address hidden>)
Branch: R4.1

commit 514af74b823f65f9a985a85688863dcdbb81db14
Author: Nischal Sheth <email address hidden>
Date: Thu Oct 12 10:08:28 2017 -0700

Use IANA assigned tunnel type for native encapsulation

Change-Id: Ib7eba8cd8610836f76fa539fa3112e26d0fb036b
Closes-Bug: 1706726

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/36476
Submitter: Nischal Sheth (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/36476
Committed: http://github.com/Juniper/contrail-controller/commit/23311c47d8fa4603722cc86722cd71a85c878107
Submitter: Zuul (<email address hidden>)
Branch: master

commit 23311c47d8fa4603722cc86722cd71a85c878107
Author: Nischal Sheth <email address hidden>
Date: Thu Oct 12 10:08:28 2017 -0700

Use IANA assigned tunnel type for native encapsulation

Change-Id: Ib7eba8cd8610836f76fa539fa3112e26d0fb036b
Closes-Bug: 1706726