with ISOLATE_ENV, it isolates the global environment between scripts
just like it did before; without it, it uses a common environment

with MINIMAL_STD, it restricts even further the available library
functions; useful for configuration files that don't need to do
actual scripting, just to define some tables

... and improve its output

All loaded scripts can now be run in a protected environment
so that they cannot do any harm to the host or to each other