Improve Fence Texture

Fences use their wood type's planks texture, but that looks bad. They should look as if their planks were vertical, not horizontal. Current fences look like they are made from small wooden cubes, not planks. Similar to what the folks that make the Vanilla Tweaks texture pack did, it should be added in the game. Of course, fence gates suffer from the same issue, and should be changed as well.