Removed uncommented and unused hibernate config.
Using new enhanced id generators (Hibernate 4)

As explained in the Hibernate 4 Doc, it is recommended to use the new enhanced identifier generators. More information: http://docs.jboss.org/hibernate/core/4.3/manual/en-US/html_single/#mapping-declaration-id-generator
Merge pull request #20 from buehner/enhanced-hibernate-config

Enhanced hibernate config