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.

- so we don't use JSP scriptlets anymore
- Used input from http://www.thymeleaf.org/petclinic.html
- also some improvements to SimpleMappingExceptionResolver make it
easier to get the error message from the JSP

- renamed
- migrated validation to bean validation

caused images not to be loaded

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

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

- added JPA annotations to POJO classes
- merged JPA Repos with Hibernate repos so we only use JPA
- renamed .txt files to .sql
- moved Spring configuration files so it is easier to use them inside
JUnit tests

- commented out all Spring MVC config related to content negociation so
the app works well in HTML for now
- Integrated Bootsrap look&Feel in the 'vets' section