Docutils: Documentation Utilities Code

Comment on control character dot or apostrophe

Font C is not available groff >= 1.23 warns about this

add variants of references not supported yet

Apply literal block patch #205. Use ``.EE`` and ``.EX`` macros to manpage.py

Thanks G. Branden Robinson for pointing out that this was fixxed sometime

Small code cleanup.

* Sort import statements.
* Do not overwrite standard `io` with `docutils.io`.
* Use auxiliary variable to avoid too long lines and
multiple dereferencing of ``self.state.document.settings``.

Auto-close `docutils.io.FileInput.source` in case of reading/decoding errors.

Small documentation fixes/additions.

Remove trailing whitespace, update links.
Add comment to structure `parsers.rst.directives` source.
Expand docstring for `utils.relative_path()`.

Test suite: Change comparison order equality tests.

Change the order in equality tests (`assertEqual`), so that in case of
failure the "diff" message will list changes in convential order:
"-" for old (expected)
"+" for new (actual output).

Revise image reading in ODT writer.

* Use `urllib.parse.urlparse()` to tell local image files from remote ones.
* Use context manager for file operations.
* `urllib.request.urlopen()` raises URLError, not HTTPError.