Compatibility: fix XEmacs compilation failures

Compatibility: fix XEmacs compilation failures

* lisp/ob-eval.el, lisp/ob.el, lisp/org-macro.el, lisp/org-mhe.el:
  Require org-macs and org-compat as necessary.
* lisp/ob-tangle.el: Declare function `org-store-link' and
  `org-open-link-from-string'.
* lisp/org-compat.el: Extend eval-and-compile clause and add advices
  for functions that have different parameter lists in XEmacs. Add
  variable definitions that XEmacs lacks .
* lisp/org-macs.el (declare-function): Define macro to use autoload
  instead for XEmacs.
* lisp/ox-html.el, lisp/ox-odt.el: XEmacs does not have table.el, so
  use 'noerror on the require form.
* lisp/ox-texinfo.el (org-texinfo-table-column-widths): Fix spliced
  argument list that XEmacs complains about by adding parenthesis.

This fixes all compilation failures on XEmacs and warnings related to
Org that indicate that XEmacs has compiled things wrongly (for
instance it might have interpreted a function as a variable symbol).
There are still many warnings that probably indicate serious problems.