Guidance on stream limitations in laziness and termination

Streams generally produce elements lazily and avoid production of excess elements when there are short circuiting operations. However, for less common cases laziness is not possible There is a tradeoff between implementation complexity and laziness.

Problematic cases arise for the following:
1. use of an "escape hatch" iterator or spliterator terminal operation
2. use of nested flatMap operations

It would be beneficial to add some guidance to the stream package documentation.