'web path to kml file' is confusing and absolute by default

In the settings form, there are two different values:
* Path to store the KML file
* Web path to the KML file

While the web path has confused me at least once in thinking this is the path to the downloadable KML file, I don't understand why it is needed.

Looking at the code, it is used only before building the downloadable KML file. For all case and matter, I believe this should be the file generated previously by the generate function, which uses the 'path to store' to store the file.

I suggest to remove the 'web path' alltogether and write/read from the 'path to store' only.

On a different note, the default value on the 'web path' is absolute URL, which breaks if the site is moved to a different domain or authentication is active on the site (e.g. http user password).