Codechange: Replace AllocatorProc with SpriteAllocator class.

This allows for state to be passed to or maintained by the allocator.

src/blitter/40bpp_anim.cpp

@@ -397,7 +397,7 @@ void Blitter_40bppAnim::DrawColourMappingRect(void *dst, int width, int height,
 	}
 }
 
-Sprite *Blitter_40bppAnim::Encode(const SpriteLoader::SpriteCollection &sprite, AllocatorProc *allocator)
+Sprite *Blitter_40bppAnim::Encode(const SpriteLoader::SpriteCollection &sprite, SpriteAllocator &allocator)
 {
 	return this->EncodeInternal<false>(sprite, allocator);
 }