Feature Request: Overlay Network Map with Floorplan

[nanobra1n]

I think it would be awesome if we could get the ability to load an image of a floorplan and pin the location of the nodes to different positions. This of course gets more complicated if you go into 3 dimensions (multiple floors), but it would be helpful to combine spacial awareness with the link qualities, so people realize that the reason the link to that node is weak because it sits behind the refrigerator.

[carldebilly]

Very similar to #135