OAK-1741: Ensure that package export version are proper for 1.0 release

Add explicit package versions to ...commons.cache and ...commons.sort.
For now 0.20 to match the version exported in the last release.

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1590701 13f79535-47bb-0310-9956-ffa450edef68