Transactions should be on the root application context (or Hibernate will not be able to persist entities)

- integrated Gordon's comments in the POM
- removed antlr from the POM that we don't need anymore
- changed webjars versions inside headTag.jsp

Changed the birth date for all the pets (so we do not have a 12 year
old hamster where their life expectancy is 2-3 years :)  )

In that way we don't need a dedicated config file for the Service layer

see https://jira.springsource.org/browse/DATAJPA-292

(feedback from Oliver Gierke)

renamed profiles and removed unnecessary@DirtiesContext annotation so the Test suite now runs in 40% less time

- there are now 3 data access implementations (jdbc, jpa and
spring-data-jpa)
- added corresponding bean profiles
- JUnit tests are now successful

There is still some polish up to be done.

- migrated to bean validation annotations
- merged to one single controller

- removed unneeded Spring config files
- moved i18n files to a dedicated folder