Evaluates a string as a chunk, and applies it to a particular CPU player.
Appears to allow all manner of AI functions & variable assignments to be called from within SP missions and gametypes.
There are all sorts of commands you'd normally call in the AI LUAs; but this function lets you tinker with them in realtime.

<iPlayerIndex>: the index number of the CPU player.
<sStringToEvaluate>: the string to evaluate.