Stairs_BuildDown

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26:Stairs_BuildDown (tag, speed, height, delay, reset)

tag: Tag of first sector in staircase 
speed: How quickly the steps lower 
height: Height of each step 
delay: Number of tics the staircase waits between steps 
reset: Tics until the stairs return to their original heights (0 if never) 

Builds a staircase in sectors marked with the Stairs_Specials.