Widgets that extend ContentPane shouldn't also extend _Container or _Contained, as those are already implemented by ContentPane.   Presentation still not working but this gets it closer (note that it wasn't working before [15974] either).
Widgets that extend ContentPane shouldn't also extend _Container or _Contained, as those are already implemented by ContentPane.   Presentation still not working but this gets it closer (note that it wasn't working before [15974] either).

Refs #7819, #8321 !strict

git-svn-id: ee6e786acc44c9cca5ee17c71a5576c45c210361@16189 560b804f-0ae3-0310-86f3-f6aa0a117693

redaktor/deliteful