this could work... alternatively (somewhat a wild idea) -- we could 
- unify naming of ```config/filter.d/*common*``` to be ```config/filter.d/<logservice>-common*```
- unify  ```config/filter.d/<logservice>-common*``` to provide ```__prefix_line```
- provide ```suhosin``` a ```<logservice>``` parameter and then ```[INCLUDES]```  ```before = <logservice>-common.conf```

not sure even if it would work (actually probably would not since inclusions yet to happen before understanding of any parameter, bbut we could work it out) -- just wanted to dump a suggestion first