RFR: 8222318 : javadoc does not accept valid HTML5 entity names

[Hannes Wallnöfer]

Please review:

Issue: https://bugs.openjdk.java.net/browse/JDK-8222318
Webrev: http://cr.openjdk.java.net/~hannesw/8222318/webrev.00/

The entities were extracted from https://www.w3.org/TR/html52/entities.json using a script.

Entities without trailing semicolon are not included (they always have a counterpart with semicolon), while entities with dual code points are listed but commented out. I have created JDK-8223868 for those entities.

Thanks,
Hannes