Switch to H2 as test DB

Current we need to support 3 DB flavours, Derby (Test), PostgreSQL and MySQL. The automatic test are run using the DerbyDB. The system tests are run using PostgreSQL.

The means MySQL isn't tested as part of the formal test, only in the local tests performed by ONB. Any functionality developed by ONB will on the other hand not be regression tested on a PostgreSQL DB before the release test.

We could mitigate some of these problems by replacing the Derby test DB with a H2 DB, where it is possible to start the DB so it emulates either MySQL or PostgreSQL sql. This would provide the followingadvantages:

• We could test both MySQL and PostgreSQl in our automatic test, by running H2 in these 2 compability modes when running the tests.
• We could avoid having to support a special devel DB flavour, thereby only having to maintain 2 sql flavours.