- Added template class base::KindOf<Type>

- Added template class base::KindOf<Type>
Currently string based representation of a Kind. Used as
Resolvable::Kind (package, patch, etc.), Capability::Kind
(named, versioned, conditional etc.; toto) and other kinds.

- Removed ResKind; A Resolvables Kind is now defined by
ResTraits<Resolvable>::KindType. Resolvable provides it as
Resolvable::Kind. Implemented as base::KindOf<Resolvable>.
(simply use Resolvable::Kind where you would have used ResKind)