Brush entity that spins in place on one axis (default Z). Use an origin brush to specify the rotation axis.
To rotate around another axis, make a func_wall with an explicit avelocity given.
-------- KEYS --------
-speed: speed to rotate (in degrees per second)
+speed: speed to rotate (in degrees per second, default: 100)
noise: path/name of looping .wav file to play.
dmg: Do this much dmg every .dmgtime interval when blocked
dmgtime: See above. (0.25s default)