(sh-mode-map): Remove bindings for

(sh-mode-map): Remove bindings for
sh-electric-rparen, sh-electric-less and sh-electric-hash.
(sh-st-punc, sh-here-doc-syntax): Use string-to-syntax.
(sh-font-lock-heredoc, sh-font-lock-paren): New funs.
(sh-font-lock-syntactic-keywords): Use them.
(sh-heredoc-face, sh-st-face, sh-special-syntax): Remove.
(sh-mkword-regexp, sh-electric-rparen-needed-here): Remove.
(sh-mode): Don't override font-lock-unfontify-region-function.
Use a copy of sh-font-lock-syntactic-keywords.
(sh-set-shell): Don't set sh-electric-rparen-needed-here.
Don't call sh-scan-buffer since font-lock does it on the fly.
(sh-get-indent-info): Use `face' rather than `syntax-table'
text-property to detect here-documents.
Replace sh-special-syntax with sh-st-punc.
(sh-prev-line): Use `face' rather than `syntax-table'
text-property to skip over here-documents.
(sh-font-lock-unfontify-region-function, sh-check-paren-in-case)
(sh-set-char-syntax, sh-electric-rparen, sh-electric-hash)
(sh-electric-less, sh-set-here-doc-region)
(sh-remove-our-text-properties, sh-search-word, sh-scan-case)
(sh-scan-buffer, sh-rescan-buffer): Remove.