* contrib/lisp/ox-deck.el: Change menu key to ?d to avoid conflict
with ox-s5.
(org-deck-toc): Use HTML_CONTAINER_CLASS instead of html-container-class.
(org-deck-headline): Simplify code to use HTML_CONTAINER_CLASS
directly, and use org-element-get-relative-level.
(org-deck-item): Use uppercase property.
* contrib/lisp/ox-s5.el (s5): Add configuration variables for S5 meta data.
(org-s5--build-meta-info): ditto.
(org-s5-headline): Simplify code to use HTML_CONTAINER_CLASS directly,
and use org-element-get-relative-level.
(org-s5-plain-list): Use uppercase property.
(org-s5-template-alist): Fix bug. (Don't try and substring nil.)
