Closes #183: Don't delete prompt when clearing REPL output

* slime-repl.el (slime-repl-input-line-beginning-position): Use
`inhibit-field-text-motion'.
Closes #182: Remove problematic `defun*' in contrib/slime-fuzzy.el

* slime-fuzzy.el (slime-fuzzy-complete-symbol): Use `cl-defun` not `defun*`