JDK-8175036 enables HTML 5 when generating the API docs.
javac runs doclint at compile time, but remains configured for HTML 4.
We should update the compilation steps to use HTML 5 except where
exceptions are needed.
Note that two modules, java.base and java.desktop, is currently not
fully html5 compliant, which generates warning which fails the build. In
this patch, they have still html5 checking disabled.
Bug: https://bugs.openjdk.java.net/browse/JDK-8180318
WebRev:
http://cr.openjdk.java.net/~ihse/JDK-8180318-enable-doclint-format-html5/webrev.01
/Magnus
