[Tilesathome] Caption for < 6

[Sebastian Spaeth]

Dirk Stöcker wrote:
> I would like to have caption layers for <6:
> 
> - Continents (up to level 0)
> - Names of oceans/seas (oceans up to 0, seas up to 3/4)
> - nation borders (up to level 4 probably)
> - probably up to 4 very large cities or names of nations

Would be great, however when I turned it on, orp was getting the
placement all wrong (pushing labels too far away from the equator). Once
this works, it should be feasible to get a lowzoom caption layer.

spaetz