Update TODO file.
Add simple tool to fetch articles from parsoid.

This will let us benchmark database size for parsoid-format articles,
versus mediawiki-markup style like the old Wikipedia activity used.
Rewrite 'test-parsoid' tool to do article conversion in parallel.

Actually seems to make all the HTTP requests at once at the beginning,
which is a little more parallelism than expected!
BOOTSTRAP PATCH: don't override height/width/cellspacing if explicitly given.
Switch to using Parsoid to render wikitext; update README.md to match.

We now use Parsoid to render wikitext, and plan on storing the parsoid-format
wikitext directly and using it as a base for editing.
Check in some notes and links for mediawiki/Parsoid stuff.