[Seaside] self request from renderContentOn

[Patrick Collison]

Thanks for the tips. I still don't fully get it, though.

> 2. Don't call components directly from the render methods of other
> components, always make sure any calls are inside #callback: blocks, this
> bites every newbie

Is there any way around this restriction? Or is it for exactly this
purpose that tasks were invented? Say it was necessary, for whatever
reason, that control flow was [request user's name] -> [display the
name], with no explicit action required to begin the process -- is
subclassing WATask the best (only?) way to do it?