[Xastir] network cygwin install

[Tapio Sokura]

Curt, WE7U wrote:
> I was thinking that the geotiff stuff was more US-centric, but if
> it's easy to add in Cygwin, then libproj and libgeotiff are a
> no-brainer.

They are both available via the cygwin installer and Xastir's 
./configure finds and includes them automatically, if they are 
installed. I'm using geotiffs for many local maps that are originally in 
a Finnish national projection (PNGs with external calibration 
information). With gdalwarp it is easy to accurately transform them into 
geotiffs and then use in Xastir. Naturally the quality of the warped 
maps is degraded a bit, but I rather have them tell the truth than look 
pretty. Also it is not a bad thing to be able to keep the map 
calibration information in the same file as the map image itself.

   Tapio