[crossfire] buttons and teleporting

[Preston Crow]

If you teleport off of a button, it stays pressed, so the next player to 
move onto it doesn't trigger it.  I ran into this with a map where a 
button triggers a teleporter and other actions on the map.  It works 
great for the first player to hit it, but then fails.  I think the 
teleporter bypasses any move off logic, but I don't see how to fix that.