Minor stuff

- reset counters in bootstrap
- discard unreachable "return 0"
New functions: copy-list, identity
Indent use join instead of !reduce #'concat-two
Unify env and fenv in a compose type lexenv

So it also replaces *env* and *fenv* with *environment*
Print returns object itself
Implement BLOCK, RETURN-FROM special operators and RETURN macro
Implicit blocks for WHILE, DOTIMES, DOLIST and DEFUN
return argument is optional and assoc uses non local exit
Update copyright year
Fix DOTIMES and DOLIST implicit NIL to ignore the optional result form