Make sure that if we fail to read the App13 (iptc) block of a JPG file, that that...

Make sure that if we fail to read the App13 (iptc) block of a JPG file, that that doesn't block other metadata from being read. Also makes sure if more then one app13 block is in the file, they are all read, not just the last one that appears in the file (This required some changes to tests since before the intermediate value was just one value, now its an array of all such blocks)