Emulate modem on sh4 serial port.
Use picotcp stack to handle ppp protocol.
Include nvmem with network settings (server at alienfront.duckdns.org,
disabled by default).
ggpo: always save delta ram on save_game_state as frames may be rerun
and resaved
Global network online status (ggpo, naomi, modem, bba)
Disable fast forward, cheats and savestates when online.
Flyinghead