[Xastir] GeoTiffs was Segfault on indexing maps

[Liz]

> 
> FWIW, the limitations of what Xastir can use for GeoTIFFs and how to
> rework unusable GeoTIFFs to be usable with Xastir are described in
> the README.MAPS file.  This file should be installed
> in /usr/share/doc/xastir by a binary package, or
> in /usr/local/share/doc/xastir for a source install.
> 

I'm passing this problem to the trained assistant. I think he
understands this far better that me  ;)