Add toAvroMap command that converts a morphline record to an Avro record that contains a Map with string keys and array values where the array values can be null, boolean, int, long, float, double, string, bytes.
CDK-535. FileSystemDatasetRepository.partitionKeyForPath breaks backwards compatibility
CDK-536: Do not call setDataModelClass in Avro 1.7.4.

The AvroSerialization.setDataModelClass method was added in 1.7.5, which
isn't available on some clusters. It is now dynamically resolved and not
called if it is not present. In 1.7.4, the only data model available is
reflect.
CDK-537: Check for empty views and return 0 splits.

This updates the FS implementation's InputFormat to check the incoming
view using isEmpty to fix the setInputPaths bug. FileInputFormat assumes
that setInputPaths is called with at least one path. MR tests have been
added for both FS and HBase.