Used in Ore no Shita de Agake.
Since the musbgm_* interface does not allow multiple channels, this
implementation uses musbgm_* for channel 0 and muspcm_* for channel 1.
- nact.h and xsystem35.h no longer include scenario.h
- Removed `sys_*` aliases in nact.h
- sys_getString() and sys_getConstString() are moved to
scenario.c as sl_getString() and sl_getConstString()
- DEBUG_COMMAND macros are now defined in scenario.h
We only support a fixed set of modules, so dynamic linking isn't really
necessary. This paves the way for running System3.9 games on more
platforms.
NIGHTDLL is temporarily disabled, because many symbols conflict with the
SACT module.
kichikuou