Optionally omit files from the bundled JRE based on Oracle README

[HybridEidolon]

http://www.oracle.com/technetwork/java/javase/jre-8-readme-2095710.html

The Oracle license provides a list of "optional" files in the JRE distribution that can be omitted if the features aren't needed. A few configuration options could be added to optionally omit those files and save space.

[tomcashman]

I'll add config options for this in the next major release.