AddStyle and IncludeStyle CSS inclusion components

["Filip S. Adamsen" <fi...@stubkjaer-adamsen.dk>]

Hi,

I just - hopefully - finished coding two CSS inclusion components.

The AddStyle component adds CSS to the <head/>'s <style/> section, while 
the IncludeStyle component includes style sheet links in the <head/> 
section. Both components must be wrapped by a Style component.

@AddStyle takes one to three parameters:

   disabled - whether to add this piece of style or not
   selector - optional selector part, e.g. selector { style }
   style    - required style part, might include selector

@IncludeStyle takes one to two parameters:

   disabled   - whether to include this style sheet link or not
   styleSheet - a required asset representing the style sheet to be added

The only catch to these components is that I had to modify the Shell 
component. All changes are backwards-compatible, though. The usual 
"stylesheet" and "stylesheets" parameters are still supported, too.

So, about the only thing I need to know before actually documenting the 
components and making a patch would be whether or not they have a chance 
of making it into the code base, preferably before the 4.0 release.

I could release them somewhere else, but I just feel that these kinds of 
components are needed in pretty much every Tapestry application, and 
hence I would be very happy to contribute them.

Please let me know what you think.

-Filip