Codechange: Replace AllocatorProc with SpriteAllocator class.

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

src/blitter/null.cpp

@@ -15,10 +15,10 @@
 /** Instantiation of the null blitter factory. */
 static FBlitter_Null iFBlitter_Null;
 
-Sprite *Blitter_Null::Encode(const SpriteLoader::SpriteCollection &sprite, AllocatorProc *allocator)
+Sprite *Blitter_Null::Encode(const SpriteLoader::SpriteCollection &sprite, SpriteAllocator &allocator)
 {
 	Sprite *dest_sprite;
-	dest_sprite = (Sprite *)allocator(sizeof(*dest_sprite));
+	dest_sprite = allocator.Allocate<Sprite>(sizeof(*dest_sprite));
 
 	dest_sprite->height = sprite[ZOOM_LVL_MIN].height;
 	dest_sprite->width  = sprite[ZOOM_LVL_MIN].width;