Get rid of a couple of copies of the CC0 text. Add header comment to
CC0 files to remind people editing them what the terms are. Also add
some missing XML headers. The header comments in layouts won't bloat
the binary - they get stripped out before compressing, same as any other
comments.
* Fix Acorn SL names so they show in the right position in front-ends.
* Fix mistake in BBC Bridge Companion. Thanks to Pernod70.
* Fixed more names. Thanks to Pernod70.
* Some more name fixes.
* Fix names for hardware manufactured by Casper and Torch.
* SL title disc lowercase for coherence.
