Merge remote-tracking branch 'spark-upstream/master' into HEAD

Conflicts:
	README.md
	core/src/main/scala/org/apache/spark/util/collection/OpenHashMap.scala
	core/src/main/scala/org/apache/spark/util/collection/OpenHashSet.scala
	core/src/main/scala/org/apache/spark/util/collection/PrimitiveKeyOpenHashMap.scala
	pom.xml
	project/SparkBuild.scala
	repl/src/main/scala/org/apache/spark/repl/SparkILoop.scala
Fix mis-merge in 44fd30d3fbcf830deecbe8ea3e8ea165e74e6edd
ClassManifest -> ClassTag
Manifest -> Tag in variable names
Take SparkConf in constructor of Serializer subclasses
Fix AbstractMethodError by inlining zip{Edge,Vertex}Partitions

The zip{Edge,Vertex}Partitions methods created doubly-nested closures
and passed them to zipPartitions. For some reason this caused an
AbstractMethodError when zipPartitions tried to invoke the closure. This
commit works around the problem by inlining these methods wherever they
are called, eliminating the doubly-nested closure.