Hadoop index task

"host" is used by the emitter. Both end up being emitted, which can be confusing.

Conflicts:
	merger/src/main/java/com/metamx/druid/merger/common/task/Task.java

New balancer

Conflicts:
	server/src/main/java/com/metamx/druid/master/DruidMaster.java

Conflicts:
	merger/src/main/java/com/metamx/druid/merger/worker/config/WorkerConfig.java

Fix DeterminePartitionsJob ISE for dimensions not present in all rows

Conflicts:
	merger/src/main/java/com/metamx/druid/merger/common/TaskToolbox.java
	merger/src/main/java/com/metamx/druid/merger/common/task/DeleteTask.java
	merger/src/main/java/com/metamx/druid/merger/common/task/IndexGeneratorTask.java
	merger/src/main/java/com/metamx/druid/merger/common/task/MergeTask.java
	merger/src/main/java/com/metamx/druid/merger/coordinator/http/IndexerCoordinatorNode.java
	merger/src/main/java/com/metamx/druid/merger/worker/http/WorkerNode.java

1) Initial commit of refactorings on top of housejester's to simplify the zipping and simplify the creation of other methods of loading data

1) Move the local cacheFile logic out of the S3 pullers into the SingleSegmentLoader
2) Make the S3SegmentPuller just pull down the file
3) Make the Loader do the unzip, ungzip, or rename
4) 2 and 3 make S3ZippedSegmentPuller not necessary (still there, just deprecated and empty)
4) Tweak the TaskToolbox so that the Pullers returned by getSegmentGetters behave the same as they did before

Conflicts:
	common/src/main/java/com/metamx/druid/utils/JodaUtils.java
	indexer/src/main/java/com/metamx/druid/indexer/DbUpdaterJob.java
	indexer/src/main/java/com/metamx/druid/indexer/HadoopDruidIndexerConfig.java
	indexer/src/main/java/com/metamx/druid/indexer/IndexGeneratorJob.java