improve/tidy up interfaces widget

Attempt 2 with ipv6 fix. Assuming the address in the screenshot is long enough.

The fix, had to change class on line 91 from "vncellt" to "listr". Which is weird as original it was "vncellt". This means we lose the alternative colour scheme. But I think it looks better then the original widget.

Ready for review

![widget](https://cloud.githubusercontent.com/assets/4223752/3987312/51072660-28a4-11e4-9451-a4ee1bd47f3f.png)