pdti-dao bug fixes, changes for easy of configurations

This pull request contains changes on my previous pull request and the followings:

- Fix potential memory leak issue
- Fix to use EntityManagerFactory instead of Hibernate SessionFactory.
- Fix JUnit test cases to use derby in memory DB and @RunWith annotation to load Spring configuration
s.
- Fix an issue that base64 encoded value is encoded twice in DSMLv2Engine.
- Support external propeties files as custom configurations and change properties files' location to src/main/resources/META-INF/spring directory
  - classpath:META-INF/spring/*.properties as default, file:pdti-server/*.properties as custom configuratinos
  - classpath:*.properties doesn't work, so that the location is changed to META-INF/spring/*.properties (Spring Roo default location)
- Fix deployment issues on glassfish3.
- Add MySQL JDBC driver.
- Support DB connection pool.