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.
* Add MIDI floppy softlist
* IMG raw sector dump misses something in the data somewhere, so use IMD instead (which decodes fine)
* Missed file name
* Add midi softlist to a couple of IBM PCs
