MULTIPLE RELEVANT CHANGES - see commit details

* migration to Spring-Data-JPA (CrudRepository)
  (Removing unnecessary dao code)
* fixed MainApp autowiring (created bean mainApp & fixed annotation based configuration)
* cleanup in pom.xml:
  - removing unnecessary dependencies
  - fixed (I think) log4j-spring dependencies
  - JPA metamodel generation moved to separate profile - probably we won't be using Criteria API