CDK-192: Add view copy command.

Crunch's MemPipeline won't write to MapReduceTargets, so the CopyTask
has to write to the output View manually. Crunch is still used to
materialize the incoming collection so that DoFn transforms can be used
later.
CDK-192: Fix csv-import to run in parallel.

This updates the csv-import command to use the CopyTask and a temporary
repository to set up a Dataset for the incoming CSV data, stored in the
same FileSystem as the data. This is compatible with the
kite-data-mapreduce formats.