1) Move up to Jackson 2.1
2) Some bugs were fixed, but they ended up getting mixed in with the Jackson upgrade :(
DeterminePartitionsJob: Select partition dimension to minimize segment size variance when cardinality is low
Merge pull request #86 from metamx/dimpartition-by-variance

Select partition dimension by variance when cardinality is low
DeterminePartitionsJob: Fix docs
Merge branch 'master' into indexing_refactor

Conflicts:
	merger/src/main/java/com/metamx/druid/merger/common/TaskStatus.java
	merger/src/main/java/com/metamx/druid/merger/common/task/DeleteTask.java
	merger/src/main/java/com/metamx/druid/merger/common/task/IndexDeterminePartitionsTask.java
	merger/src/main/java/com/metamx/druid/merger/common/task/Task.java
	merger/src/main/java/com/metamx/druid/merger/common/task/V8toV9UpgradeTask.java
	merger/src/main/java/com/metamx/druid/merger/coordinator/MergerDBCoordinator.java
	merger/src/main/java/com/metamx/druid/merger/coordinator/RemoteTaskRunner.java
	merger/src/test/java/com/metamx/druid/merger/coordinator/RemoteTaskRunnerTest.java