Refactor CLI Parsing and Main Library to Use Functional Style

There are still bugs to work out, but this refactor is aimed to respect functional style.  

## Command-Line Parsing
The separate command-line parsing functions (one for each sub-command) have been replaced by a single function that engages in meta-parsing.  It pulls a "definition" from a CSON file `argument_definitions.cson` and uses that to direct its actions.   Adding or editing sub-commands is much cleaner now.

## Main Library
This is a little buggy still.  I pulled out repetitive code and am making use of the `lift` function, instead of manually wrapping functions in promises.  I also added a `set_aws_creds` function so that each function that makes a call to AWS does not have to know an external state.  It is self-contained and stateless.