Activates/deactivates a given commodity object. (An inactive object doesn't perform its function on its input - it just passes it on to the next object.) The activation depends on the value of 'true'; if it's TRUE the object is activated, if it's FALSE it's deactivated. All objects are created in the active state except for brokers; remember to activate your broker when you have linked your other objects to it.
INPUTS
co
a pointer to a commodity object
true
boolean telling whether the object should be activated or deactivated
RESULT
The activation state of the object prior to the operation. (0 is also returned if 'co' was NULL.)