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/vid_voodoo_render.c

@@ -1266,8 +1266,11 @@ static void voodoo_half_triangle(voodoo_t *voodoo, voodoo_params_t *params, vood
                                 if (cca_invert_output)
                                         src_a ^= 0xff;
 
-                                if (params->fogMode & FOG_ENABLE)
-                                        APPLY_FOG(src_r, src_g, src_b, state->z, state->ia, state->w);
+                                if (voodoo->type != VOODOO_BANSHEE) /*HACK*/
+                                {
+                                        if (params->fogMode & FOG_ENABLE)
+                                                APPLY_FOG(src_r, src_g, src_b, state->z, state->ia, state->w);
+                                }
 
                                 if (params->alphaMode & 1)
                                         ALPHA_TEST(src_a);