Change restart skip -> continue in src/util.lisp

* src/util.lisp (header): updated copyright
  (run-handler-with-restarts): changed restart `skip' -> `continue'
Improved establishing of restarts in src/util.lisp

* src/util.lisp (run-handler-with-restarts): do not cons up intermediate
  list for multiple values
  (with-hook-restarts): likewise