Infinispan/JGroups subsystem check for and correct diffs in the default config we ship vs. what we persist

https://github.com/wildfly/wildfly/pull/7184#issuecomment-75439059

Brian:

Semi-tangent: could you guys check for and correct diffs in the default config we ship vs. what we persist? E.g.

1) Start a new server running standalone-full-ha.xml
2) Use cli to add a system prop (just to force persistence)
3) Diff standalone-full-ha.xml vs standalone/configuration/standalone_xml_history/standalone-full-ha.initial.xml

There shouldn't be changes other than the added system prop. Any changes mean either our default configs are wrong or the marshalling is wrong. Both should match xsd. I did this for another reason a couple weeks ago and saw some changes in the clustering subsystems. Perhaps this PR fixes the problem, but I have a feeling I saw something else besides this.