Added Voodoo Banshee emulation.

Known issues :
- Tiled framebuffer layout is not yet implemented. This causes horizontal
  offsets in some 2D 16bpp stuff (eg FMV in Tomb Raider 2, UI in Expendable)
- Fog is broken and currently disabled for Banshee
- Possibly at least 1 race in 2D blitter emulation
- A few things not yet emulated - overlay filters, some (rarely used) 2D
  blitter functions

src/video.c

@@ -50,6 +50,7 @@
 #include "vid_wy700.h"
 #include "vid_t3100e.h"
 #include "vid_t1000.h"
+#include "vid_voodoo_banshee.h"
 
 enum
 {
@@ -82,6 +83,7 @@ typedef struct
 
 static VIDEO_CARD video_cards[] =
 {
+        {"A-Trend Helios 3D (Voodoo Banshee)",     "banshee",        &atrend_voodoo_banshee_device,     GFX_BANSHEE,         VIDEO_FLAG_TYPE_SPECIAL, {VIDEO_BUS, 2,  2,  1,  20, 20, 21}},
         {"Acumos AVGA2 / Cirrus Logic CL-GD5402",  "avga2",          &avga2_device,                     GFX_AVGA2,           VIDEO_FLAG_TYPE_SPECIAL, {VIDEO_ISA, 3,  3,  6,   5,  5, 10}},
         {"ATI Graphics Pro Turbo (Mach64 GX)",     "mach64gx",       &mach64gx_device,                  GFX_MACH64GX,        VIDEO_FLAG_TYPE_SPECIAL, {VIDEO_BUS, 2,  2,  1,  20, 20, 21}},
         {"ATI Video Xpression (Mach64 VT2)",       "mach64vt2",      &mach64vt2_device,                 GFX_MACH64VT2,       VIDEO_FLAG_TYPE_SPECIAL, {VIDEO_BUS, 2,  2,  1,  20, 20, 21}},