RFR: JDK-8160728: Update compare script to clean baseline

[Erik Joelsson]

Several things have happened recently that affect the compare script's 
ability to do clean comparisons for build change verification.

* The SystemModules.class has even more randomness in it and it 
currently doesn't look like it can be reliably compared at all.
* The new lib/classlist file may have lines in different order between 
builds.
* Support comparing the new licensee-src build mode.

By fixing this I'm again able to do a full -testset buildinfra JPRT 
COMPARE_BUILD build using an empty patch and get a clean result.

Bug: https://bugs.openjdk.java.net/browse/JDK-8160728
Webrev: http://cr.openjdk.java.net/~erikj/8160728/webrev.top.01/

/Erik