fire_out
========

An output function that implements an exponential race model by treating the state
levels (multiplied by `rate`) as the rate parameters of an exponential process
for each unit.  Thus the time between steps varies.  When a step occurs, the output
of the unit that has won this race is a copy of its state; all other outputs are 
zero.

Parameter
=========

	parameter	default_value
	rate		1