SI-4332 Plugs the gaps in views

These currently result in runtime errors:

    scala> List(1).view.distinct.force
    java.lang.UnsupportedOperationException: SeqView(...).newBuilder

    scala> List(1).view.inits.toList
    java.lang.UnsupportedOperationException: SeqView(...).newBuilder

Two tests are enclosed:

  1. reflect on the views to make any method that returns
     `Repr` is overriden in `*ViewLike`. This guards against
     new additions to the collections API.
  2. exercise the newly added overrides

Parallel collections views are not touched, as these are likely
to be deprecated or removed shortly.