Correct initialization script file's name

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 :)  )

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

- 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

+ removed unused script

+ improve mysql script to prevent data from being added if it's already present

+ improve DataSource setup

+ improve DataSource setup

+ moved db files around
+ moved JPA/AOP META-INF/ files into the webapp classpath