added _parentUID, resolution of root as special, and ** for set intersection, fixed isTop tagging
initial super-ref split in grammar, absclafer, and intclafer
added BaseClafer super kind
updated regressions : <primitive> to ->
positive tests : <primitive> to ->
fixed stats for abstract/concrete + reference clafers
tracing
string analyzer
all code compiles, resolver does not find reference types
common: remove idToPExp
references resolved correctly
"" and "clafer" super -> _super = Nothing, _parentUID: "root" for top-level

super :: Maybe ISuper, sClaferId :: PExp, rClaferId :: PExp