hg: lambda/lambda/jdk: Replace 'average' with 'arithmetic mean' for clarity

[brian.goetz at oracle.com]

Changeset: eb9b9342c22e
Author:    briangoetz
Date:      2013-06-26 21:14 -0400
URL:       http://hg.openjdk.java.net/lambda/lambda/jdk/rev/eb9b9342c22e

Replace 'average' with 'arithmetic mean' for clarity

! src/share/classes/java/util/DoubleSummaryStatistics.java
! src/share/classes/java/util/IntSummaryStatistics.java
! src/share/classes/java/util/LongSummaryStatistics.java
! src/share/classes/java/util/stream/Collectors.java
! src/share/classes/java/util/stream/DoubleStream.java
! src/share/classes/java/util/stream/IntStream.java
! src/share/classes/java/util/stream/LongStream.java