Improved referencing of hibernate configuration file in persistence.xml

Based on JBIDE-10470 issues there are some improvements suggested for hibernate.cfg.xml referencing in persistence.xml:
1. When postgres.cfg.xml is located is src of home project, there is "/postgres.cfg.xml". It looks like absolute path (slash).
Can this be changed to relative path form? (just "postgres.cfg.xml")?
2. If there is required project with defined cfg.xml file located in srt, there should be relative path used as well (I expect this should work as well)
3. For anything else there could be be an absolute path (with slash like /home/user/workspace/prj/cfg/postgres.cfg.xml)