add remarks about the missing TOP case; searched for all occurrances of "topological" and "continuous" to make sure all other mentions of TOP have been expunged; other minor changes

for job in `./externalization-jobs.sh`; do
	pdflatex --jobname $job tikz-figures.tex;
	rm $job.log;
	rm $job.out;
	rm $job.aux;
done