JSON+++

- ozCore
  * JSON
    + get() & asXXX() merged -> asXXX( defaultValue )
    + more tolerable, on type mismatch default value or NIL is returned rather
      than crashing with an error
    + asArray() return number of elements read
    + templates for generic as<numType>(), asArray<numType>()
    + type-specific add() and include() removed since not needed any more
      because of implicit ctors