Remove references to `org-protected' `org-example' and `original-indentation'
* lisp/org-macs.el (org-if-unprotected, org-if-unprotected-1,
org-if-unprotected-at): Removed macros.
(org-re-search-forward-unprotected): Removed function.
* lisp/org.el (org-format-latex): Remove reference to `org-protected'.
* lisp/org-list.el (org-list-struct): Remove reference to
`org-example' and `org-protected'.
* lisp/org-footnote.el (org-footnote-at-reference-p): Remove reference
to `org-protected'.
* lisp/org-capture.el (org-capture-fill-template): Remove reference to
`org-protected'.
* contrib/lisp/org-wikinodes.el (org-wikinodes-process-links-for-export):
Remove reference to `org-protected' value.
These text properties were used by the old export framework. They are
not needed anymore.