Fix Birch Leaves "Color-Locking" for Resource Pack Creators

Birch leaves are the scariest part of creating a Minecraft texture pack. The texture file itself is gray, but their in-game appearance not affected by the foliage.png colormap file, as the color for the block is coded into the game. Because of this, the color of birch leaves cannot be (easily) changed without using a mod like Optifine. I don't know anything about coding, so forgive me if I'm wrong, but it seems that the simple solution would be to remove this code and recolor the birch leaves texture.