[publican-list] clean_ids strips carriage returns inside <screen> tags

[David O'Brien]

Is this by design or accident?

e.g., if you use <screen> tags to display a multi-line command, and then 
use a backslash and CR to indicate that the command continues on the 
next line, clean_ids strips out the CR.

This seems at odds with what DocBook expects of <screen>:

'This element is displayed “verbatim”; whitespace and linebreaks within 
this element are significant. Screens are usually displayed in a fixed 
width font.'

Same thing happens in <programlisting>, but that's not really the right 
tag to be using anyway.

Using version=3.0.0 on F16 (yes, I'm a bit behind).

Cheers
-- 

/David