[SCXML] Accepted: make <final> optional as child of <scxml>

We have provisionally decided to accept the following change request for inclusion in the next version of the spec.  <final> will be optional as a child of <scxml> (and <state>).

 

>From Torbjorn Lager:
 
 I don't think a <final> as a child of <scxml> should be required. Some systems
just don't need to ever terminate!