Decouple framework from scripts

[jdevera]

It does not make much sense that users are forced to check in the main script with their subs. Ideally, this could be an option, or they could just add it as a submodule.

Decoupling feature means support for having one instance of sub installed that would be able to drive several subs. So sub would then work as a framework. Users can then upgrade sub and get the latest additions into their subs.

Having an internal command to create a new sub would probably help.