GeoDistances is a little application with the purpose of constructing a kind of
maps we will name 'range distance maps'.

Range distance maps define, for each pixel in a given original background map
and a set of waypoints, a color based on the distance from the given pixel
to its nearest waypoint.

Colors are defined in ranges, for example:
- White for pixels less than 100 km from a point
- Green for pixels between 100 and 1000 km from a point
- Etc.

The usage of the application is:

python geodistances.py GPX_MAP MAP_DEFINITION OUTPUT_IMAGE

where:
- GPX_MAP is a zipped gpx file.
- MAP_DEFINITION is a xml file that define background image, borders and 
ranges.
- OUTPUT_IMAGE is the image that will be generated. It can be in different 
formats depending on the Python Imaging Library (PIL) on the system.

The main target users of this application are users of geocaching.com that
can receive gpx files of their found geocaches.