Feature: support inlining other languages

[lmorg]

This is an experimental idea but basically a feature where you can inline Bash / Go / whatever. Some code has already been laid down for this but really it should be given a lower priority over other features. Just an interesting challenge from an engineering perspective

[lmorg]

Unfortunately without supporting the retrieval of env vars set by the inlined languages, this concept creates hidden traps as well as uglier code.

Plus murex is flexible enough that you could write inlining functions in murex code so support doesn't need to be backed into the shell itself.