Updates for VWF script replication changes

Update for changes in https://github.com/virtual-world-framework/vwf/pull/329.

@eric79, can you review?

I think of it as a little stronger than parenthetically *(optional)* since those parameters are usually not needed. You can stop reading after *The second parameter is optional...*.

(OK, the `this` is usually needed, but that can be improved.)

I updated the phrasing for *third parameter*....