add lean version of a dotenv reader supporting load of multiple .env files
inspired by python-dotenv and django-dotenv (https://github.com/jpadilla/django-dotenv) but both are lacking the load of env variables from multiple .env files (to prevent redundancy).
- local project development/tests settings: source-parent-folder contains variables for all projects and project root folder additional variables for the project.
- web server runtime settings: home folder contains variables for all websites, and project root folder additional variables for project.
Edited by AndiEcker