Change of mtu is not handled by reclass. Example interface:
```
        br_ctl:
          enabled: true
          type: bridge
          proto: static
          mtu: 1450
          address: ${_param:single_address}
          gateway: ${_param:ctl_gateway}
          netmask: ${_param:control_network_netmask}
          use_interfaces:
          - ${_param:primary_first_nic}
```

Change-Id: Iec857e4ac374b7787892144c772063796be87c4b

This enables a more fine tuned dpdk for better performance.
More details on pmd-rxq-affinity config:
http://docs.openvswitch.org/en/latest/howto/dpdk/

Change-Id: I630c6af94ff733619fb175f522fc515984862ff6

Allows configuring general section as well as configuring
    each dhcp enabled interface separetly.
    Does not allow alias or lease configuration.

We need to save our manualy managed interfaces to different directory to
workaround salt bug that causes interface deconfiguration in
/etc/network/interfaces for interfaces manualy configured in
/etc/network/interfaces.d

Upstream-Bug: https://github.com/saltstack/salt/issues/40262

Config:

linux:
  network:
    tap_custom_txqueuelen: 10000

in case of configuration parameter defined will create file:

/etc/udev/rules.d/60-net-txqueue.rules

with content:

KERNEL==”tap[0-9a-z\-]*", RUN+="/sbin/ip link set %k txqueuelen 10000"

Add possiblity to add ip address and mtu on dpdk ovs bridge to
be able use VXLAN as tenant segmentation.

Change-Id: I1394d30c5d9935218841b17ff7651dac7b4abefa
Epic: PROD-8957

Introduce dpdk support for linux OVS configuration.
It configures dpdk interface bind, ovs dpdk ports, bonding,
parameters for dpdk cpu pmd and set multique queues for specific
ovs dpdk interfaces.

Change-Id: I3f38660bab8db0c2b38f03ed8c94eb10b6b3beb9
Epic: PROD-8957
Epic: PROD-8958

"names" makes a separate call to the package management frontend to
install each package, whereas "pkgs" makes just a single call so that it
improves performance.

Change-Id: I48f912c9d966c99d78cd2e89b605a2d016afe18b

Before adding new records to /etc/hosts, remove all hostnames
that are managed by the model but have different addresses
than provided in the model.

Change-Id: Idf5a30429497c33027e6ba973e684ba0443a1edf

Parameter purge_hosts will enforce whole /etc/hosts file, removing entries
that are not defined in model except defaults for both IPv4 and IPv6 localhost
and hostname + fqdn.

It's good to use this option if you want to ensure /etc/hosts is always in a
clean state however it's not enabled by default for safety.

Change-Id: Ieb219b2dd494d5a66ecc52a2ec00dd5157ee2b7a

This reverts commit bedfa10ae6.