The XHTML standard encompasses the XML standard.
From the beginning, the XML standard [1] has always included required
support for five character entities:
1. the ampersand (&) as &
2. the left angle bracket (<) as <
3. the right angle bracket (>) as >
4. the double-quote character (") as "
5. the apostrophe or single-quote character (') as '
See section "2.4 Character Data and Markup" of the XML standard [1]
for further details.
Add support for the character single-quote character entity (')
in order to fully support XHTML pages.
[1]: https://www.w3.org/TR/REC-xml/
Signed-off-by: Kyle J. McKay <mackyle@gmail.com>
