ox: Move a function in the file

* lisp/ox.el (org-export--copy-to-kill-ring-p): Move function
  elsewhere in the file.
ox-html.el (org-html-indent): Default to nil

* ox-html.el (org-html-indent): Default to nil, as non-nil can
break indentation of source code blocks.

Thanks to Vladimir Lomov for reporting this.
org.el (org-modules): Remove deleted libraries, add new ones

* org.el (org-modules): Remove deleted libraries, add new
ones.
org.el (org-display-inline-images): Use the #+attr_html: :width syntax

* org.el (org-image-actual-width): Update docstring.
(org-display-inline-images): Use the #+attr_html: :width syntax.