This is an attempt at generating nice map tiles for slippy maps at low zoom
levels which can then be combined with OpenStreetMap tiles from higher zoom
levels. The information in the OpenStreetMap database is intended for higher
zoom level and doesn't work well when viewing the whole world or a whole
continent.

The approach here is to generate maps for the whole world, annotate them
with text from an SVG file and the split the image into tiles. Probably not
the best way of doing things, but seemed easiest for the moment.

To run this yourself you need:
* GMT for creating the maps
* Inkscape for adding labels
* Ruby with the RMagick gem for splitting up the maps into tiles

Run it from this directory by calling:
$ bin/doit

Currently the color scheme from OSM Mapnik is used, so that the tiles fit
in with normal Mapnik tiles. Look at
http://geo.topf.org/map/index.html?type=wmapnik&lon=20&lat=39&z=2 to see
this in action.