autodetect java version and configure world accordingly (now that aj is stricter about not allowing java 5 features at < 1.5 level, this was needed for some LTW tests to pass too)
This is the beginning of a significant refactoring needed to cleanly support generics. We need to be much crisper about when we have an unresolved type (plain old TypeX) and when we have a resolved type. This refactoring renames TypeX to UnresolvedType and ResolvedTypeX to ResolvedType. In addition, it moves a number of methods that were defined on TypeX but which can only be answered by resolved types down onto ResolvedType. At the moment, ResolvedType still extends UnresolvedType - but a ResolvedType is *not* a UnresolvedType and this inheritance of convenience will be broken down the line so that ResolvedType does not extend UnresolvedType. Full signature information can only be known for ResolvedTypes.