[Xastir] no zoom levels under 15 with osm maps

[Piotr Gluszenia Slawinski]

> All good ideas- but first I have to get code working that will map
> coordinates to tile numbers. There are examples, and I'll use them as
> starting points. The tiles will be cached with names that match the
> server structure, so downloading additional tiles could be done a
> number of ways- both within and external to Xastir.
>
> ...jerry
>

it would be also great if tile directory would be compatible
with other mapping software, i.e. tangogps ,
so i.e. ~/Maps/

to prevent redundant disk space usage...