Configurations should not hold on to classes

```
Configurations should directly not hold on to classes because these will be old 
class versions in GemStone/S.

Options include
- holding on to a Symbol and doing a lookup (may have impact for dialects with 
namespaces)
- holding on to the association/binding from Smalltalk
```

Original issue reported on code.google.com by `philippe...@gmail.com` on 22 Aug 2014 at 6:38
