More parser work: fixed a few bugs with [[intlinks]] in headers, a bug that caused the paragraph parser to return an empty string, and added a warning/backup-and-restore for when a render stage returns an empty string.

#!/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