Add an execution module that does primitive parsing on state and execution module fns.

[cro]

What does this PR do?

It is sometimes helpful to know all the execution and state module functions that exist. The Salt loader and sys.doc go a long way to providing that, but are unable to return modules and functions that do not have current dependencies installed. This execution module does some primitive parsing on all the .py files in the modules and states directories and returns a dictionary keyed by module and function name. Each dictionary entry contains a list of arguments that the function can take.

This module also contains a second function that returns a list of all functions that take the test argument (for dry runs, aka test=True)