(sgml-quick-keys): New variable.

(sgml-quick-keys): New variable.
(sgml-mode-map): Use it, defined additional long keys to compensate.
(sgml-tag-alist): Added <![ ]>
(sgml-tag): Special treatment for previous construct.
(sgml-auto-attributes): Deleted variable covered by sgml-quick-keys,
changed function of same name.
(sgml-delete-tag): Newline also counts as whitespace before tag.
(html-quick-keys): Use sgml-quick-keys as default, thus changed to nil.
(html-mode-map): Added C-c C-c char combinations for when
html-quick-keys is nil.
(html-tag-alist): Added /cgi-bin/ to href completions, submit (spelling
fixed) button to form.
(html-checkboxes): New skeleton.