@CD and dropped tag item interaction

[Jeff Kingston]

The problem here is that if a list item is not wide enough to take
up the entire column, then any centring etc. inside it is done with
respect to the width actually consumed, not the total width.  So
something like

   @LI {
          @CD { Should be centred }
          And here is the rest of the item
       }

will centre "Should be centred" above "And here is the rest of the item"
rather than centring it in the whole column as desired.

Of course, if instead of a list item this thing had been one entry in
a table, then one would expect Lout to do what it did.  Trouble is,
Lout doesn't know the difference.

There is a workaround for this kind of thing that probably is not
documented in the user's guide, or maybe just in passing.  You can
use the @HExpand symbol to gobble up all available horizontal space
on behalf of the following object.  So the workaround in the case
above is to type

   @LI @HExpand { ... }

It could be argued that @LI should incorporate @HExpand, but then it
would be a disaster inside tables.  This is a good example of the
occasional penalties you pay for generality.

Jeff.