RFR: JDK-8223319: Add copyright footer to specs and man pages

[Erik Joelsson]

The (optional) specs and man pages should have the same copyright footer 
as the generated API docs. This patch adds the logic to add such 
footers. It also removes the existing footer in jvmti.html.

Bug: https://bugs.openjdk.java.net/browse/JDK-8223319
Webrev: http://cr.openjdk.java.net/~erikj/8223319/webrev.01/index.html

/Erik