Make the project git repo a configuration value

[freephile]

There are actually two places where the source repository for Meza is referenced in code:

1. The getmeza.sh bash shell script
2. The playbooks and roles of Meza

In the first case, we'll provide for overrides by setting environment variables.

In the latter cases, we'll provide for overrides with variable precedence (using -e 'foo=baz' extra-vars of Ansible.) https://docs.ansible.com/ansible/latest/playbook_guide/playbooks_variables.html#understanding-variable-precedence

[freephile]

The Meza repository URL is only currently used within Yaml/Ansible scripts as part of the Autodeployer functionality. It is not used to control the working sources of a controller. It is a nuance that must be better explored and documented for use cases so that any changes or enhancements reflect user expectations.