If, in src/lvleditor/lvleditor_display.c you change the starting zoom from 3 to
24, you can get a good "world" map :P
It may not cover the entire world map, but us can do a "Town Surroundings",
"Hell Fortress" and "Disruptor Shield Base" maps pretty well. You might want
delete the Town Obstacle Names to them don't mess your "World Map" and move the
buttons. I've made a patch (that IS NOT on RB) testing it and showing it
efficiency. It include two packages: One with less than 1 KiB: The patch and
another one to you place in graphics/mouse_buttons - Make sure to backup the
folder - That will make the Level Editor buttons transparent, replacing them
with alpha images.

You can make a temporary world map with it: It's already a start. :P

LINK: http://www.mediafire.com/download/bgj5c7d52jqcc82/World_Map_Generator.zip