Now that Jenkins is using java8 there are a few libraries that should possibly be removed.

There are 2 versions of Stax api (jdk8 ships with a stax api and most likely imp)
javax.activation is part of JDK8 (and prior JDKS - Jenkins shipps with a patched version?)
javax.annotation is shipped with jdk8 - but missing the SQL annotations - but it is not likley that Jenkins usses those and should be able to make do with the Resource/Resources and PreConstruct/PostConstruct).

There may also be other libraries...