Executables! They execute, they parse, they rock.

To put a reference to ANY executable variable just do this:
">>>variable<<<"

examples: ">>>x<<<", ">>>x0<<<", ">>>etc<<<"

Prepends are currently ONLY run for 'python' language, so they're the
only one we can ensure executes...

They go in a LIST of commands to be executed. These are stuck together
as one string later on with '\n' going in between items. However,
writing them as a list makes it MUCH easier to read in the JSON file.