[Seaside] No error message if DNU when downloading scripts from WAScriptLibrary subclasses

[Yar Hwee Boon]

If a DNU (for eg., forgetting to put a ^) is raised while downloading  
scripts through the WAScriptLibrary (and I guess styles from  
WAStyleLibrary too) mechanism, the error message is only viewable if you  
explicitly do a download of that script file. Should there be a debug  
link? Since there was a discussion of logging the transcript contents as a  
panel in the webpage, maybe it would be useful to show an error message  
there?

-- 
Regards
HweeBoon
MotionObj