Add IP address to status bar

This addresses issue ev3dev/ev3dev#184.

@dlech Here's my attempt at adding the IP address. I tested it and the IP label successfully unbinds and rebinds when the IP address changes.

Unfortunately, I wasn't able to emulate the feature in the desktop test, so it just shows "???.???.???.???" so that you can see where it would be. If you would like me to try to get it to work on the desktop, I can give it another shot.
No, "WasabiFan" is not my real name. It was actually the first result from an Xbox Live gamer tag generator from when I first registered for Xbox Live; I just decided to keep it as a user name.

I generally try to keep my real name off the internet (although I have made a few mistakes/exceptions). In this case, I guess I'll just use the user name. Legally speaking that won't make much of a difference, but it really doesn't matter in this case (I would laugh at anyone who wanted to claim this file as their own :smile:).