RFR 8014824: Document Spliterator characteristics and binding policy of java util collection impls

[Paul Sandoz]

Hi,

The following patch updates documentation for various spliterators:

  http://cr.openjdk.java.net/~psandoz/tl/JDK-8014824-split-docs/webrev/

Mostly this is just clarifying stuff that was missing, but there are a few cases of a spec change to Collections (CCC will be created):

  http://cr.openjdk.java.net/~psandoz/tl/JDK-8014824-split-docs/specdiff/overview-summary.html

This is for the Collection.empty/singleton/nCopies relaxing the reporting of characteristics for spliterators containing 0 or 1 elements. It's more efficient to share code for empty and singleton spliterator implementations (and instance for the former) rather than attempting to conform the required characteristics of the collection, which will anyway have little or no benefit in terms of the client trying to optimize based on those characteristics.

Paul.