org-element: Rename accessors

org-element: Rename accessors

* contrib/lisp/org-element.el (org-element-property,
  org-element-contents): New functions, renamed from, respecively
  `org-element-get-property' and `org-element-get-contents'.
(org-element-link-successor): Small refactoring.
(org-element-drawer-interpreter,
  org-element-dynamic-block-interpreter,
  org-element-footnote-definition-interpreter,
  org-element-headline-interpreter,
  org-element-inlinetask-interpreter, org-element-item-interpreter,
  org-element-special-block-interpreter,
  org-element-babel-call-interpreter,
  org-element-comment-interpreter,
  org-element-comment-block-interpreter,
  org-element-example-block-interpreter,
  org-element-export-block-interpreter,
  org-element-fixed-width-interpreter,
  org-element-keyword-interpreter,
  org-element-latex-environment-interpreter,
  org-element-property-drawer-interpreter,
  org-element-quote-section-interpreter,
  org-element-src-block-interpreter, org-element-table-interpreter,
  org-element-verse-block-interpreter,
  org-element-emphasis-interpreter, org-element-entity-interpreter,
  org-element-export-snippet-interpreter,
  org-element-footnote-reference-interpreter,
  org-element-inline-babel-call-interpreter,
  org-element-inline-src-block-interpreter,
  org-element-latex-fragment-interpreter,
  org-element-link-interpreter, org-element-macro-interpreter,
  org-element-statistics-cookie-interpreter,
  org-element-subscript-interpreter,
  org-element-superscript-interpreter,
  org-element-time-stamp-interpreter,
  org-element-verbatim-interpreter, org-element-map,
  org-element-parse-elements, org-element-parse-objects,
  org-element-interpret-data,
  org-element-interpret--affiliated-keywords,
  org-element-normalize-contents, org-element-swap-A-B,
  org-element-backward, org-element-drag-backward,
  org-element-drag-forward, org-element-forward,
  org-element-mark-element, org-narrow-to-element,
  org-transpose-elements, org-element-unindent-buffer,
  org-element-up): Use new names.
* contrib/lisp/org-export.el (org-export-get-inbuffer-options,
  org-export-use-select-tags-p, org-export-get-min-level,
  org-export-data, org-export-skip-p, org-export-interpret-p,
  org-export-collect-footnote-definitions,
  org-export-footnote-first-reference-p,
  org-export-get-footnote-number, org-export-get-relative-level,
  org-export-last-sibling-p, org-export-inline-image-p,
  org-export-resolve-fuzzy-link, org-export-resolve-id-link,
  org-export-resolve-ref-link, org-export-resolve-coderef,
  org-export-expand-macro, org-export-get-loc,
  org-export-handle-code, org-export-collect-elements,
  org-export-get-genealogy, org-export-get-previous-element): Use new names.
* EXPERIMENTAL/org-e-ascii.el (org-e-ascii--current-text-width,
  org-e-ascii--build-title, org-e-ascii--build-caption,
  org-e-ascii--list-listings, org-e-ascii--list-tables,
  org-e-ascii--unique-links, org-e-ascii--describe-links,
  org-e-ascii-template, org-e-ascii-drawer, org-e-ascii-emphasis,
  org-e-ascii-entity, org-e-ascii-export-snippet,
  org-e-ascii-export-block, org-e-ascii-fixed-width,
  org-e-ascii-headline, org-e-ascii-horizontal-rule,
  org-e-ascii-inline-src-block, org-e-ascii-inlinetask,
  org-e-ascii-item, org-e-ascii-keyword,
  org-e-ascii-latex-environment, org-e-ascii-latex-fragment,
  org-e-ascii-link, org-e-ascii-paragraph, org-e-ascii-quote-section,
  org-e-ascii-statistics-cookie, org-e-ascii-subscript,
  org-e-ascii-superscript, org-e-ascii-table, org-e-ascii-verbatim,
  org-e-ascii-verse-block): Use new names
* EXPERIMENTAL/org-e-latex.el (org-e-latex--wrap-label,
  org-e-latex-drawer, org-e-latex-emphasis, org-e-latex-entity,
  org-e-latex-example-block, org-e-latex-export-snippet,
  org-e-latex-export-block, org-e-latex-fixed-width,
  org-e-latex-footnote-reference, org-e-latex-headline,
  org-e-latex-link--inline-image, org-e-latex-latex-fragment,
  org-e-latex-latex-environment, org-e-latex-keyword,
  org-e-latex-item, org-e-latex-inlinetask,
  org-e-latex-inline-src-block, org-e-latex-special-block,
  org-e-latex-radio-target, org-e-latex-quote-section,
  org-e-latex-plain-list, org-e-latex-src-block,
  org-e-latex-statistics-cookie, org-e-latex-table--format-string,
  org-e-latex-target, org-e-latex-time-stamp, org-e-latex-verbatim):
  Use new names
* EXPERIMENTAL/org-e-publish.el (org-e-publish-collect-index,
  org-e-publish-index-generate-theindex): Use new names.