------
* improved 68k accuracy (initial reset timing + auto-vectored interrupts handling).
* modified Z80 & 68k cores to directly use external cycle count instead of intermediate counters.
* improved Z80 & 68k cpu execution/synchronization accuracy, now use Master Clock as common clock reference.
* improved PSG & FM chips synchronization with CPU execution (fixed point precision).
* completely rewrote sound output processing & mixing: sound chips are now clocked with exact output frame rate
to ensure 100% smooth video & audio playback, with no lag or skipping, while still rendering an accurate number
of samples per frame. This will also make fast-forward implementation (video AND sound) more trivial.
* improved color accuracy in VDP highlight mode to match results observed on real hardware.
* improved sprites processing timing accuracy: fixes (un)masked sprites in Mickey Mania (3D level), Sonic 2 (VS mode).
* improved horizontal blanking & HINT/VINT occurrence timing accuracy, as measured on real hardware.
* improved H-Counter accuracy in 40-cell mode, as measured on real hardware.
* optimized Z80 bus status signals
* usual code cleanup
[GCN/WII]
---------
fixed ASNDLIB exit when returning to game
fixed audio/video startup sync
modified audio back-end engine according to new audio processing core (see above)
~ modified LFO implementation to make it handles signed displacement value correctly (is that correct ? still need to be verified against real hardware)
