Add operators
Minor changes
Add support for lists
Ensure the whole file is parsed
Enhanced List built-ins
Deeply reduce lists (in parallel)
Put Lisp code in its own file
Support constant functions
Some Lisp improvements
  - support let-expression
  - fix List parsing: support lists starting with \n
Lisp: add support for a restricted let*
Lisp: support trailing spaces/newlines in lists
Fix node substitution