OpenStreetMap improvements

Hi! I just pushed some big changes to OpenStreetMap.

• You can update OpenStreetMap without having to re-upload the maps
  
• The app uploader can now be run when OpenStreetMap is installed to manage maps and see which areas are recorded
  
• You can now have multiple map areas installed at once, and they can be different sizes and scales
  
• Support for much larger map areas uploaded than before
  
• The OpenStreetMap maps app can now zoom in and out (via a menu when you press the button)
  
• The currently recording track in the 'recorder' widget should now be plotted in the openstmap app if there is GPS - but I haven't been able to test this yet
  
  

... and a few more things. The quality of zooming is not amazing but this still seems like a huge improvement.

Really the main thing we need to sort out is the filtering of OSM maps into 3 bit color - if anyone has any contributions I'd love to see them (maybe it's best to start dithering)