RFR: JDK-8011920 (Main implementation classes for java.util.stream)

[Brian Goetz]

This is a review request for the bulk of the java.util.stream 
implementation; webrev at:

   http://cr.openjdk.java.net/~briangoetz/JDK-8011920/webrev/

You might ask: with 15,000 lines of new code, why are there no tests?

The simple answer is: we've got plenty of 'em, but they can't be put 
back until all the source goes back.  So until then, I'll just show you 
the coverage report for java.util.stream:

   http://cr.openjdk.java.net/~briangoetz/JDK-8011920/Coverage.pdf

So...we have tests.  We'll put them back soon.