* lisp/progmodes/ps-mode.el: Use SMIE. Move string and comment recognition

* lisp/progmodes/ps-mode.el: Use SMIE.  Move string and comment recognition
to syntax-propertize.
(ps-mode-auto-indent): Mark as obsolete.
(ps-mode-font-lock-keywords-1): Remove string-or-comment handling.
(ps-mode-font-lock-keywords-3): Use symbol regexp operators instead of
word regexp operators.
(ps-mode-map): Move initialization into declaration.  Remove binding
for TAB, RET, >, ], and }.
(ps-mode-syntax-table): Move initialization into declaration.
Don't give word syntax to non-word chars.
(ps-run-mode-map): Move initialization into declaration.
(ps-mode-menu-main): Remove auto-indent entry.
(ps-mode-smie-rules): New function.
(ps-mode): Setup smie, syntax-propertize, and electric-indent-mode.
(ps-mode-looking-at-nested, ps-mode-match-string-or-comment): Remove.
(ps-mode--string-syntax-table): New const.
(ps-mode--syntax-propertize-special, ps-mode-syntax-propertize):
New functions.
(ps-mode-newline, ps-mode-tabkey, ps-mode-r-brace, ps-mode-r-angle)
(ps-mode-r-gt, ps-mode-r-balance): Remove functions.