Interfaces Widget Fixes

1) Send the IPv4 address "strong" in functions.inc.php (line 339) so that it is displayed strong on each update - forum: https://forum.pfsense.org/index.php?topic=85187.msg469639#msg469639
2) IPv6 address did not update or appear in the regular updates, it stayed locked at whatever happened to be displayed when the dashboard was first rendered. Add code to actually get and pass the IPv6 address in the background AJAX updates.
3) Interface status change (e.g. pull the cable, transition from up (green arrow) to down (red arrow) - green arrow was changing to blank box. This was because the div for the red arrow was not created on the initial display of the widget, so the AJAX to attempt to display it failed. In interfaces.widget.php create all the various div for each possible status icon, displaying only the relevant one, also always create the divs for IPv4 and IPv6 address - there might be a null address on first display, but after plugging in the cable an address might come and we want a div for the AJAX to put the address text into.

For me, that seems to make the interface status (icon GIF), IPv4 and IPv6 addresses come and go on the dashboard as I plug/unplug cables and interfaces get and lose DHCP addresses...