Add DynMethods support for hidden implementations.

The new hiddenImpl builder method will get a declared method (which may
be private) and attempt to set it to be accessible.
CDK-549: Add DoFn transform to copy and import commands.

This adds --jar and --transform options to the copy and import commands.
The jar option will add a jar to the distributed cache and the current
classloader. The transform option is the name of a DoFn class that will
be instantiated and used to transform GenericRecord objects. It must
produce GenericRecord objects.
Add configurable ClassLoaders to dynamic helpers.
CDK-549: Use new ClassLoader for user-supplied transforms.

Before this, the addJars method was invoking addURL on the current
loader, which is a hidden method and isn't allowed on secure JVMs. This
commit uses the ClassLoader handling from obj-schema to load the
user-supplied transform class and create a TransformTask. This also adds
a addJars method to the TaskUtil configuration helper.
CDK-549: Add class validation for transformed values.
CDK-549: Add tests for transform DoFns.
CDK-549: Improve error message when DoFn cannot be loaded.
CDK-549: Revert changes to copy, add transform.

This adds a "transform" command to transform records via copy from one
dataset to another. The copy command is now purely a copy.
CDK-579: Add kite.uri option to maven plugin.

This deprecates repository URI and dataset name by adding a kite.uri
option for a dataset URI. If the dataset URI isn't present, then the old
behavior is used and a warning is logged.
CDK-579: Remove namespaces from maven plugin calls.

This was cherry-picked from a version with namespaces.
CDK-565: Update FS writer to pass properties to Configuration.

This allows users to configure the Parquet settings, like
parquet.block.size, by setting properties on the descriptor. Descriptor
properties are copied to the Configuration object that FileSystemWriter
now uses to initialize its Appenders.

Closes #175.
CDK-539. Convert demo example to use views.
CDK-539: Add FileSystemDatasets.viewForUri.

This adds a conversion utility that creates a view from a Path or URI
within a FileSystemDataset. This will allow the demo example to continue
using paths from Oozie but no longer depend on the partiiton API.
Add javadoc
CDK-526: Added --version option to the Main CLI

Closes #178.
CDK-479: Added a CDH5 app parent pom

Closes #177.
CDK-591: Detect the correct package for the Parquet SerDe to work with Hive 0.13
CDK-203: Add sync to DatasetWriters.

For Avro and CSV FileSystem appenders, sync is implemented as flush
followed by hsync. For Parquet, there is no implementation because there
is no way to flush or sync parquet files. For HBase, sync calls flush.

This adds tests for CSV and Avro sync behavior, which doesn't currently
work for the local FS, but does for HDFS.