Add <a href='geo:xxx,yyy'> elements to HTML content in GPX files

```
http://en.wikipedia.org/wiki/Geo_URI

When asked for, OKAPI could detect and parse some common location patterns put 
inside cache descriptions and log entries, then surround them with <a 
href='geo:xxx,yyy'> elements. Geo URIs are recognized by a growing number of 
mobile devices.

```

Original issue reported on code.google.com by `rygielski` on 1 Jun 2014 at 10:20
