WebIOPi... Don't even bother!
Alright... frustration... just wasted at least an hour or so trying to get WebIOPi working on RPi2, only to learn that more or less the WebIOPi project is dead. Apparently the developer behind it was hired away by a company called myDevices to use WebIOPi as the backend for their product Cayenne. The developor, Eric Ptak, stated back on 1 Sep 2015 that "That’s a very good news for all of you as I have to work for the DIY and makers communities as a part of my new job position."
However, that was 8-months ago, and the project has not updated since. It was never updated for RPi2 much less the newest RPi3. In other words... DEADEND! If you'd like though, you could "Get Started for Free" on Cayenne, but I'm not risking getting half-way down that path and having to pay to finish my project nor do I wish to get shoehorned into a proprietary solution. One goal here is to be as open sourced as possible.