Major improvements in the security of the CAPTCHA system (no SQL injection or anything like that); fixed denied form submission due to _af_acting on form object wrongly switched to true

#!/bin/bash
for f in *.svg; do
    echo Converting $f
    fname=`echo $f | cut -d '.' -f 1`
    rm -f $fname.png
    inkscape -z -f $f -w 22 -h 22 -e ./$fname.png
done