Update version to 0.9.1-SNAPSHOT
Add more logging for better diagnostics & debugging
CDK-260: Fix PartitionExpression for DateFormatPartitioner.

This moves the toExpression(FieldPartitioner) method into the
PartitionFunctions class. This allows accessor methods to be
package-private and puts the expression logic for both directions in one
place to avoid oversight.
CDK-260: Revert change to TestMetadataProviders.
CDK-266: Use random UUIDs for unique file names.
Fix tools example.
CDK-273. Flume Log4jAppender produces spurious batch size warning.
add log message for better diagnostics
CDH-16616: MapReduceIndexerTool and SolrSink and HBaseMapReduceIndexerTool should fail fast if zk does not contain solrconfig.xml
CDK-249. Hive partitions are not created in the metastore.
CDK-249: Update for recommendations on PR#8.

This alters the partitionAdded signature to use a String rather than a
StorageKey. This removes the need to alter StorageKey and to expose the
dirnameForValue method through the Accessor. In addition, the partition
logic is kept in FileSystemDataset and PartitionedDatasetWriter rather
than in FileSystemWriters. When calling partitionAdded, the
implementations now pass the String path component that was actually
used to create the writer.
Remove file uniqueness limitation fixed in CDK-266.
Add release notes for 0.9.1.