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.
greatly improving performaces (e.g. Manic Miner demo went from 20% to 380%
ingame). Plus added some very preliminary softlists. [David Haywood]
(MESS) spectrum_cass.xml: added very preliminary softlist containing some
interesting test case for emulation. [David Haywood]