getting rid of SNode.getRoleOf
getting rid of SNode.getRoleOf
removed SNode.getRoleOf
attach/detach moved to SNodeBase
got rid of SModel.isRoot in MPS code
got rid of SModel.isRoot in java code
SModel.isRoot removed
ChildrenList in SNode can filter by role
getChildren(role) returns ChildrenList
fix tests (make and fix node contract xml)