DBUtil: utility functions for service classes using JPA
ConferenceService: use DBUtil

Use DBUtil also in unit test
ConferenceServiceTest: remove println() calls
Merge pull request #18 from stoewer/master

DBUtil: utility functions for classes and tests with JPA

LGTM
Model: change relationships from List to Set
JPA: switch from hibernate to eclipse link
ConferenceService: implement get() and create()

Unit test for new methods
Build: remove unused dependencies

- remove hibernate
- remove javaJpa
Merge pull request #20 from stoewer/master

Solved several small issues with JPA

LGTM
fixed small issues with naming, imports
Merge remote-tracking branch 'upstream/master'
fixed model changes