Fixed i161/i150

Changed rule:
if group cardinality is 0..*, all children have default card of 1.1
if group cardinality is not 0..* all children have default card of 0..1

see [i150](http://gsd.uwaterloo.ca:8888/question/682/or-group-keyword-has-different-semantics-than)
see [i61](http://gsd.uwaterloo.ca:8888/question/254/children-of-all-groups-other-than-default-should)