Fix warnings in dime.el

[cgay]

Using DIME @ version 9d2891e these warnings appear in the *Messages* buffer:

Loading /Users/cgay/dylan/workspaces/dylan-emacs-support/dylan.el (source)...done
dime.el: Warning: Use keywords rather than deprecated positional arguments to `define-minor-mode' [5 times]
dime.el: Warning: Obsolete calling convention for 'sit-for'
dime-repl.el: Warning: Use keywords rather than deprecated positional arguments to `define-minor-mode' [2 times]