Once the Sequence "synch_sequence" starts, with BT.CPP 3.X

it is impossible for **AbortCondition** to stop it.

In BT.CPP 4.X we modified our Controls and Decorators to

prevent this potential issue.

Now, when a Synchronous child is executed, **RUNNING is returned** before moving to the next child.

In this way, we give the opportunity to the tree to check ReactiveSequences or other Conditions.

From a practical point of view, this means that we must call **tick()** more often.

This new behavior should NOT introduce any additional latency, at least not a significant one.

When Controls and Decorator return RUNNING, the method `Tree::sleep()` will **not**

block and won't introduce any additional delay. This is the reason why you should never use

"normal" sleep functions.

To make this new behavior more explicit, the method `Tree::tickRoot()` was removed,

and we introduce these two new methods instead:

- `Tree::tickOnce()` works as usual. It should run inside a while-loop.

- `Tree::tickWhileRunning()` has its own while-loop, and will continue ticking until either

SUCCESS or FAILURE is received.