also convert/pngcrush png pictures with 16bit/channel (resulting in 8bit/channel) and repage their layers (as I found out that some of the pics had their layer offset the actual visual area, which makes the picture look blank in gimp)
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>get-task-allow</key>
<true/>
</dict>
</plist>