Pre-requisite: Image gallery must be activated
What does this feature do?
If you save an image with an external link, it will create a cached copy in the system gallery (tiki-browse_gallery.php?galleryId=0).
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{img src=http://avantech.net/AT-RGB.jpg}
Will become:
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{img src=http://demo.tiki.org/show_image.php?id=1}