Horizon Navigator added

Added Horizon Navigator. You can slide and rotate the map and the horizon view changes.

The core game idea behind is good, but I  currently lack the skills to make it.
It needs pretty 3D terrain to be worthwile.

Made as a break from working on Underground Stuff.
It's helpful to work on something else for a while to avoid burn out.
I learned a lot, including things that will be useful for Underground Stuff.
So even though I couldnt get the idea in my head translated into a game, it's been good to work on this.
But it's been a month now, it's time to move on.