Validate multicast ip range in Cisco N1kv Plugin

Do the validation of multicast ip range in Cisco N1kv Plugin and send
appropriate parameters to VSM.

Change-Id: Iaa1288d8a6deb2a2f32b263d4556dde8938d75f5
Closes-Bug: #1282754
NVP LBaaS: check for association before deleting health monitor

    Bug #1243129 suggests to check for associations before deleting
health monitor in DB logic, so NVP advanced LBaaS should also Change
its operations when deleting a healthmonitor.

Change-Id: I57677cc4b65a13df9f72ec689f34771c7af6a57e
Closes-Bug: #1254639
Check vxlan enablement via modinfo

On some linux distribution, for RHEL 6.5 as an example, vxlan is
enabled but the kernel version is still 2.6. And some linux kernel
version is higher than 3.8 or even 3.11, its vxlan mod may be
disabled. Under both situation, vxlan enablement checking via linux
kernel version may not be correct.

In this patch, we check vxlan enablement via modinfo: if vxlan module
exists and functional test pass, vxlan is enabled.

Closes-Bug: #1267682

Change-Id: Id52c04b4739d2d11fe52d4b1631cb4f39e6b577f
Added missing l3_update call in update_network

Change-Id: Id907ae692140fd52762ef6ac4fc1613897eb5065
Closes-Bug: #1259125
Create new IPv6 attributes for Subnets

* Introduces two new optional attributes for Subnets:
  * ipv6_ra_mode
  * ipv6_address_mode

Both attributes accept the following values:

* dhcpv6-stateful
* dhcpv6-stateless
* slaac

In addition to these values, additional behaviors are specified for
when only one of the attributes is set. For example, a Neutron network
that uses a physical router as a gateway, that transmits ICMPv6 Router
Advertisement packets to configure hosts on the network will create
Neutron Subnets that have ipv6_ra_mode *not* set, and ipv6_address_mode
set to 'slaac' so that Neutron will calculate EUI64 addresses for
each port assigned to the subnet, and not spawn a Dnsmasq process.

These attributes maintain backwards compatability with the enable_dhcp
Subnet attribute, by requiring a subnet with these attributes to also
have enable_dhcp set to True.

DocImpact

Implements bp ipv6-two-attributes
Change-Id: I5b2313fff5dca1c16ff939fdc4397d7f95ba3ba5
Calculate stateless IPv6 address

In order to support stateless IPv6, neutron should calculate IPv6 address base
on IPv6 prefix and MAC address via EUI-64 specification.  This change adds
common library to calculate IPv6 address.

Partially-implements bp ipv6-two-attributes
Co-Authored-By: Xu Han Peng <xuhanp@cn.ibm.com>

Change-Id: I68ccbc42388ec760d6fead242e080822ca753913
Merge "NVP LBaaS: check for association before deleting health monitor"
Merge "Check vxlan enablement via modinfo"
Merge "Create new IPv6 attributes for Subnets"
Merge "Calculate stateless IPv6 address"
Merge "Added missing l3_update call in update_network"
Merge "Validate multicast ip range in Cisco N1kv Plugin"