Data requirements

1. Track as georss 2.0 (http://cyber.law.harvard.edu/rss/rss.html)
   1. One track per channel
   2. Track name in title
   3. Track name in filename (without spaces)
   4. Track line symbology in category (somehow)
   5. One entry per narrative entry (with interpolated position)
   6. One entry per requested position (with interpolated position)
2. Exercise data as kml (http://code.google.com/apis/kml/documentation/kml_tags_21.html#polygon)
3. File layout & utilisation as illustrated at http://www.gliffy.com/publish/1316907/

Business requirements

1. Select what data to export (tracks, annotations)
   1. Using visible property (existing)
2. Select period of data to export
   1. Using visible property (filter to time period, existing)
3. Select frequency to export track data
   1. Using drop-down menu (in wizard)
4. Select target directory
   1. Using file-system browser (in wizard)
5. Offer to zip them up
   1. Using tick-box. We need to get a filename if we do (in wizard)

Data tests

1. Empty layers object
2. Two tracks, some narratives, some annotations
   1. All tracks, all narratives, all annotations. Check all data present.
   2. Hide one track, Hide some points, hide some narrative entries, hide some annotations. Export them. Check data
3. One track. 15 minute fixes. Narrative entries at 1,5,10,22 minute times.
   1. Check correct interpolation.