GyroGears is now DBMS independent

I've just regenerated and tested some of my commercial GyroGears applications on PostgreSQL. I've added rules and definitions both for InnoDB and for PostgreSQL in Gyro. Firebird and Oracle should now work (I'll test it these days with Oracle XE). I'm systematically dropping MySQL/InnoDB in favor of PostgreSQL, which seems more suited to GyroGears applications - nicer API, mature transactional model, nicer support, friendlier tools and no Oracle nor Larry Ellison to sue me.