Merge pull request #647 from jerryshao/master

Reduce ZippedPartitionsRDD's getPreferredLocations complexity from O(2^2n) to O(2^n)
Merge pull request #605 from esjewett/SPARK-699

Add hBase example (retry of pull request #596)
Merge remote-tracking branch 'milliondreams/casdemo'

Conflicts:
	project/SparkBuild.scala
fix typo and coding style
Update ASM to version 4.0
Add support for Spark on Yarn on a secure Hadoop cluster
upmerge with latest mesos/spark master and fix hbase compile with hadoop2-yarn profile
Merge pull request #654 from lyogavin/enhance_pipe

fix typo and coding style in #638
Fix some dependency issues in SBT build (same will be needed for Maven):

- Exclude a version of ASM 3.x that comes from HBase
- Don't use a special ASF repo for HBase
- Update SLF4J version
- Add sbt-dependency-graph plugin so we can easily find dependency trees
Merge branch 'master' of github.com:mesos/spark
Enable building a fat jar for the Spark REPL
edit according to comments
some format modification
small format modification
small modify in DAGScheduler
Allow other twitter authorizations than username/password
Add Python timing instrumentation
Prefork Python worker processes
Add tests and fixes for Python daemon shutdown
Rename PythonWorker to PythonWorkerFactory