Comment fixes.
Added support for LLCondition to AIThreadSafeSimple.
Changes to LLThread

* Call a virtual terminated() that by default sets mStatus to STOPPED,
  instead of setting it to STOPPED directly, allowing to override
  the behavior of a LLThread derived class when the thread is about
  the exit.
* Make setQuitting() public, so it can also be used to hint to a
  thread that it should stop at its earliest convience.
Added AIStateMachineThread