Update from Tibor's main branch.
Resolve some generic types and a literal.
Add some test data for DBUnit.
Fixes #69 In many to many associations one side has to be the owner and
one side has to be the inverse end (it will be ignored when updating the
relationship values in the association table). References:

http://docs.jboss.org/hibernate/annotations/3.5/reference/en/html/entity.html
http://stackoverflow.com/questions/12552714/many-to-many-hibernate-inverse-side-ignored
Sonar corrections.
Merge branch 'master' of git://github.com/MiquelSanahuja/mTor