Fix variable scoping

[lmorg]

The old code is still there and is salvagable. So hopefully it shouldn't be a massive task

[lmorg]

Ended up rewriting the whole lot but also included code for branching functions so code can run in a containerised config space. The point being you can pull the vars and config from one function but then create new local vars and alter the config without affecting the original function (aside from creating / modifying globals and modifying variables already defined).

I still need to re-write the garbage collector for variables.

[lmorg]

Garbage collector written, tested and working in branch: variable_scoping_rewrite

Will get merged into master later this week.