Watching endermen in gamemode 3

This bug allows people that are in spectator (gamemode 3) to act on endermen.

What I expected to happen was...:
I spawned an enderman to see what's happening when you're spectating an enderman.

What actually happened was...:
When I watched the enderman to get his view, he growled and then he teleported himself.

Steps to Reproduce:
1. Get in spectator game mode (/gamemode 3)
2. Find or spawn an enderman and stare him
3. Watch away and the enderman will teleport himself.