[MC-56879] Stairs don't rotate.

Stairs only orientate facing east, whether placed upside down or right-side up.

Environment

Windows 7 Home Premium, Java Version 7 Update 60

Please don't put down the affected version as a future version! You DON'T have access to it yet!

Duplicate of MC-56865

When I made the post the snapshot had just come out, the bug tracker hadn't updated to show the newest snapshot. I've updated it.