(ps-mode-print-function): Remove quote for

(ps-mode-print-function): Remove quote for
lambda expression.
(ps-mode-menu-main): Submenu with options on/off was replaced with
a toggle button.
(ps-mode, ps-run-mode): Define with `define-derived-mode'
(ps-mode): Autoload cookie added on same line as comment
(ps-mode-tabkey, ps-mode-backward-delete-char):
(ps-mode-r-balance): Replace `delete-horizontal-space' and
`indent-to' with `indent-line-to'
(ps-mode-print-buffer, ps-mode-print-region): Use `funcall'
instead of `eval'.
(ps-mode-print-region): Use `with-temp-buffer'.
(ps-run-start): Use of `mapconcat'.  Use `apply' instead of
`eval'.
(numerous places): Add back-tick and tick around names in
docstrings, fix punctuation in docstrings, remove trailing spaces.