CHOP-48. CHOP-49. Interact with avro/non-avro cell values.

Allow users to interact with avro and primitive cell values from a Kiji
table as Scala types in Chopsticks.
Handle conversions to Scala during table reads and conversions back to
Java during table writes.

Reviewed by: kiyan, robert
CHOP-54. Adds ability to run scripts with the chop script.

Use 'chop script' to run scripts and 'chop job' to run compiled jobs.

Reviewed by: kiyan