[maven-release-plugin] copy for tag v0.9.1-rc3

[maven-release-plugin] copy for tag v0.9.1-rc2

[maven-release-plugin] copy for tag v0.9.1-rc1

[maven-release-plugin] copy for tag v0.9.0-incubating

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Revert "Update version to 0.7.3-SNAPSHOT"

This reverts commit e5fbdac.

Release v0.7.1

Use new Spark EC2 scripts by default

Merge branches 'subtract' and 'bettersplits' into bizo

* subtract:
  Add RDD.subtract.

* bettersplits:
  Update more javadocs.
  Tweak test names.
  Remove fileServerSuite.txt.
  Update default.parallelism docs, have StandaloneSchedulerBackend use it.
  Change defaultPartitioner to use upstream split size.

Conflicts:
	core/src/main/scala/spark/scheduler/cluster/StandaloneSchedulerBackend.scala
	core/src/test/scala/spark/ShuffleSuite.scala