[Seaside-dev] #839 Support inline CSS and JavaScript

[Philippe Marschall]

Currently we do not allow inline CSS or JavaScript content (unless you
subclass WAHtmlElement). Every CSS and JavaScript you add the root
ends up as a document handler in the session. This obviously doesn't
work when you don't have a session. It also hurts you when you want to
go for maximum points on PageSpeed Insights. I see two possible ways
forward:

- Add checks to WAContentElement and WAHtmlRoot and check whether we
have a session.
- Add an additional method to WAContentElement for setting the inline content

Opinions? I'm leaning towards the second one.

 [1] https://github.com/SeasideSt/Seaside/issues/839

Cheers
Philippe