Revert "Refs #97 - Make SendEmailCommand extend Command."

This reverts commit 95ed653d49bfc7068826c8ca0232b537c29e39ed.
Revert "Refs #97 - Add configuration to commands."

This reverts commit ed52dbae4ab0907c3581c62ed13b78ad4d875f6e.
Refs #97 - Inject input definition into input object.

Effectively a passthrough for whatever parameters are set on Resque jobs.
Refs #97 - Run application initializers on commands in Resque.