fix map tiles

[rors]

@rors will break up this issue into smaller ones

• upload new desaturated / cropped map to rectification site
• add rectification points with Simon
• create new tiles in TileMill with terrain map background, and more zoom levels

[simgan]

Do we need the layer buttons? And the icons are still out of place, but I don't know if that's because of the old map.

[rors]

Made some progress on this. new tiles up on the live site. Still need to generate the background terrain tiles. I'll ask Andreas for help with this.

[rors]

last bit of work for this is in separate issue here: #79