Fix of t1056 - PartialFunction

type T was not recorgnized as a SAM type because a case was missing in zeroParamClass.
Fix of t112606A - path dependent types

Needed an extra case in isSubType.
Fix of t1123 - Unit discarding

Need to do unit discarding also in selection prototypes.
More tests
Fix for t1292 - legal prefixes

The original test is now in error because the type Meta in the prefix Meta#Event
is not stable and contains an abstract member Slog.

Even after removing Slog, the test in pos was still in error because the bound type parameters
were incorrectly recognized as abstract members. This has been fixed by the changes to Types.
Fix of t1280 - type of self

The type of self name "x" was taken to be the thisType of the current owner.
But the current owner was a local dummy of the class in question, so the ThisType
was NoPrefix. Inserting an enclosingClass fixes the problem.
Fix of t1236: higher-kinded

(and also of t0625, which reappeared).

Several fixes were made. In summary:

1. Naming and representation of KigherKinded traits changed. It's now $HigherKinded$NIP where
the letters after the second $ indicate variance (N)egative, (I)nvariant, (P)ositive. The HKtraits
themselves are always non-variant in their parameters.

2. When deriving refined types over higher-kinded types, the variance of a type alias
is the variance of the new type constructor.

3. isSubTypeHK was changed, as was the position from where it is called.

4. appliedTo also works for PolyTypes.
More tests, currently disabled

Mostly Java interop tests which are not yet supported. The test infrastructure for Java ocmpilation and the java parser from Scala are still missing.