If ebib is missing then the jump function from org-bibtex-extras.el
will be used if defined, else no jump function will be used.
Only call `org-bibtex-process-bib-files' on html export so that
ox-bibtex may be used for latex export without bibtex2html being
installed.
* contrib/lisp/ox-bibtex.el (org-latex-link, org-html-link): New
functions.
(org-bibtex-citation-p, org-bibtex-get-citation-key): Update function
to support "cite" links.
(org-bibtex-process-bib-files): Also look after "cite" links when
building citation list.