Apply stumble and drunken walk events to vehicles and elytra

[Tisawesomeness]

• If the player is riding a vehicle, the stumble and drunken walk events will randomly move the vehicle similarly to how it affects players on the ground.
• If the player is gliding with an elytra, the stumble event randomly rotates the player's facing direction for a short time (drunken walk not included, that would be evil).

[Thorinwasher]

I will test it out a bit, sooner or later. Found one thing though. Also isn't one of the ranges for pitch or yaw only (0, pi).