Allow a null start date in search index.
Initial Leveson scraper/parser.
[Taylor] Initial scraper/parser.
[Taylor] Spot alternative affirmation title.
[Taylor] Tweaks to narrative spotting.

Including "^" in exhibit lines, and a couple of dated special cases
issues.
[Taylor] Tweaks to interviewer spotting.

Including manual names after closed sessions, and slight alternatives to
question headings.
[Taylor] Corrected transcripts have appeared on the official site.
[Leveson] Move (sworn/affirmed) to narrative from title.
[Leveson] Reset witness each morning, fix one issue arising.
[Leveson] Include the manual correction ignored in normal parsing.
[Leveson] Remove middle names of speakers.
[Leveson] Ignore transcript that dupes another.
[Taylor] Use different instance label.
[Taylor] Store timings to be used by speeches.
[Taylor] Spot quoted Q/As, tweak paragraph spotting.
[Leveson] Move name prettifying to parser.

This makes it a bit simpler, and also fixes an issue whereby a section
heading was being incorrectly shrunk by being treated as a name.