Images can now be displayed in 3 different ways:
- 'inline': display image directly in tree view (default)
- 'icon': display only an icon, show a full screen preview
of the picture on click
- 'thumbnail': display image directly in tree view, show a
full screen preview of the picture on click
set resize="<width>,<height>" in the field tag definition to
make the server return a resized version of the image.
Useful for saving bandwidth when dealing with large images and to
have uniform image sizes (aspect ratio is mantained by filling
emtpy areas with transparent background)
