Consistent Automation evaluation:

Consistent Automation evaluation:

Rule #89: The *owner* of each automation-control is responsible to
evaluate automation of automated automation-controls (and emit Changed()
signals to notify the GUI and slaved controls).

This can happen during run(), when the Processor evaluates automation
(eg. PluginInsert does that), but needs to regardless, every cycle.
Emit Changed signal for GainControl

This follow the same concept as PluginInsert: The Changed signal
is called on demand when evaluating automation.