RFR : 8025910 : (s) Rename Stream.substream(long) -> skip(long) and remove substream(long, long)

[Mike Duigou]

Hello all;

As promised on the lambda-libs-spec-experts mailing list I have prepared a changeset which renames the single arg substream() to skip() and remove the two arg substream() method (aka "slice").

The rationale behind these changes is:

 - skip() is easier for new users to locate than substream().
 - substream(long,long) has ambiguous semantics and duplicates skip().limit()

http://cr.openjdk.java.net/~mduigou/JDK-8025910/1/webrev/
http://cr.openjdk.java.net/~mduigou/JDK-8025910/1/specidff/overview-summary.html

Cheers,

Mike