Add full support for comments in MOROS Lisp

[vinc]

This PR add full support for comments in MOROS Lisp. Previously comments where striped in the main code source but not in other files loaded with the load function, and the naive comment stripping had known bugs. Comments will now be parsed directly during the parsing step.

The error output will be a little worse for the main code source but it will be consistent with the load function. Better context will be added later.

In MOROS Lisp comments start with the char # like in Perl, Ruby, and Python instead of the traditional ; to be consistent with the shell and the shebang character sequence at the beginning of scripts: #!/bin/shell or #!/bin/lisp.

# Line comment
(def (fibonacci n) # Inline comment
  (if (< n 2) n
    (+ (fibonacci (- n 1)) (fibonacci (- n 2)))))