With the class definitions being read from XML files at startup, it seems to be
not necessary any more to store them in the database. An improved startup
performance of appserver could be a result of removing the gnue_* database tables.

Also, it would be possible to include things in the class definition that don't
fit too well into a relational database, for example default values for properties.

On the other hand, it would not be possible any more to access the class
definitions through the normal data interface.