NP2kai's two rhythm engines open different spellings, lowercase for
the built-in one and uppercase for fmgen, and nothing folds case,
so the uppercase names are files of their own rather than aliases.
fmgen's 2608_RYM.WAV fallback is opened without the directory and
is no longer claimed under np2kai/.
The np2kai shared group declared font.rom as a second required file
while NP2kai reads it only when FONT.ROM, which System.dat already
declares, is absent. Case-sensitive platforms packed the font twice.
A shared group may now add a second spelling only where some code
opens that spelling itself, as the two rhythm engines do.
Abdessamad Derraz