Starting to move Gump to using Java 11

All,

Since Tomcat's main development branch now requires Java 11, I have 
started the process of moving Gump over to Java 11.

So far, I have added Java 11 to the packages installed by Puppet.

I want to confirm that Java 11 has been installed, then I'll switch 
JAVA_HOME to point to Java 11 rather than Java 8. In theory that should 
'just work'. When it doesn't (optimistic soul that I am), we'll have to 
see what fails and figure out the best way to deal with each issue.

Once everything is running smoothly on Java 11, then I'll remove Java 8.

Mark