Worker wrapper package

This change defines the package that will be used by the worker wrapper
program. It implements the interface defines in the standalone interface
spec for the wrapper process.

It tests the library with a bunch of simple scripts that exercise each
of the components of the interface.
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Stream stdout to gearman
Change the way we handle the data fields
Close the file argsparse
Merge pull request #8 from Clever/worker-wrapper-library

Worker wrapper package