Implement a 32bpp SSE2 palette animator. This is ~4x faster than 32bpp-anim's.

Create a new blitter mode: 32bpp-sse2-anim, which is 32bpp-anim + this.
32bpp-sse2-anim is now used by default where 32bpp-anim would have been.
Also use this with the 32bpp-sse4-anim blitter mode.

Fix memory leak in current 32bpp animated blitters.

src/blitter/32bpp_sse_func.hpp

@@ -138,7 +138,7 @@ IGNORE_UNINITIALIZED_WARNING_STOP
 static inline Colour AdjustBrightneSSE(Colour colour, uint8 brightness)
 {
 	/* Shortcut for normal brightness. */
-	if (brightness == Blitter_32bppBase::DEFAULT_BRIGHTNESS) return colour;
+	if (likely(brightness == Blitter_32bppBase::DEFAULT_BRIGHTNESS)) return colour;
 
 	return ReallyAdjustBrightness(colour, brightness);
 }