inheritance does not work for DAO classes

```
Inheritance works partially only for DTO classes,
but not for DAOs.

<table name="xy" extends="yz".../>

Reason: preprocess.xml - supercolumns do not work as expected.


```

Original issue reported on code.google.com by `vbarta...@gmail.com` on 11 Jun 2010 at 7:39
