FORGE-1443 database.action property is drop-and-create

The default Java EE persistence provider is based on JPA 2.1, where you
have all those standard properties that should be supported by all
providers. So Forge sets one of those properties (database.action) to
drop-and-create. It also adds some DDL schema generation properties.
Merge pull request #365 from ivannov/FORGE-1443

FORGE-1443 database.action property is drop-and-create