Add support for IPv6 network setting

Add IPv6 setting in network setting page.
- Add IPv6 domain name, DNS servers, NTP servers enable/disable
- Add DHCPv6 enable/disable
- Add IPv6 default gateway
- Add IPv6 addresses
- Add IPv6 static addresses
- Add IPv6 static addresses adding and deleting

Tested:
- IPv6 domain name, DNS servers, NTP servers enable/disable function
- DHCPv6 enable/disable function
- Verified the IPv6 default gateway
- IPv6 addresses adding and deleting
- Verified the IPv6 addresses in IPv6 table

Change-Id: I9eebf6ef5f7de748f79779d8168b8dcfcdda2495
Signed-off-by: Sean Zhang <xiazhang@nvidia.com>
diff --git a/src/locales/en-US.json b/src/locales/en-US.json
index 8ba7ac9..44a63de 100644
--- a/src/locales/en-US.json
+++ b/src/locales/en-US.json
@@ -703,16 +703,21 @@
     },
     "pageNetwork": {
         "dhcp": "DHCP",
+        "dhcp6": "DHCPv6",
         "domainName": "domain name",
         "dns": "DNS server",
         "fqdn": "FQDN",
         "hostname": "Hostname",
+        "ipVersion": "Version of IP",
         "interfaceSection": "Interface settings",
         "ipv4": "IPv4",
         "ipv4Addresses": "IPv4 addresses",
         "ipv6": "IPv6",
+        "ipv6Addresses": "IPv6 addresses",
         "linkStatus": "Link status",
         "macAddress": "MAC address",
+        "gateway": "Gateway",
+        "ipv6DefaultGateway": "IPv6 Default Gateway",
         "network": "network",
         "networkSettings": "Network settings",
         "ntp": "NTP server",
@@ -728,7 +733,9 @@
             "dhcpConfirmTitle": "%{dhcpState} DHCP",
             "editHostnameTitle": "Edit hostname",
             "editMacAddressTitle": "Edit MAC address",
+            "editIPv6DefaultGatewayTitle": "Edit IPv6 Default Gateway",
             "gateway": "Gateway",
+            "prefixLength": "Prefix Length",
             "ipAddress": "IP address",
             "staticDns": "Static DNS",
             "subnetMask": "Subnet mask"
@@ -736,11 +743,15 @@
         "table": {
             "addDnsAddress": "Add IP address",
             "addIpv4Address": "Add static IPv4 address",
+            "addIpv6Address": "Add static IPv6 address",
             "addressOrigin": "Address origin",
+            "prefixLength": "Prefix Length",
             "deleteDns": "Delete DNS address",
             "deleteIpv4": "Delete IPv4 address",
+            "deleteIpv6": "Delete IPv6 address",
             "editDns": "Edit DNS address",
             "editIpv4": "Edit IPv4 address",
+            "editIpv6": "Edit IPv6 address",
             "gateway": "Gateway",
             "ipAddress": "IP address",
             "subnet": "Subnet mask"