Add support for send_start and send_stop from UI

### Purpose

Adds support for send_start and send_stop from the UI
Also adds necessary API endpoints

### Details:

* Add API endpoints to support send_start and send_stop
* Adding tests for send_start and send_stop
* Start using NODE_ENV instead of a manual development flag
* Adding support for configuration files
* Include sample config files, roll all config logic into env test
* Put a 'command-repeater' class on a command if the config file says it's a repeater
* Adding JS logic to handle send_start and send_stop (with 'as good as possible' edge case support)
* Overhauling README
* Rev to 0.0.7