Implode the given <list> (resp. the short descriptions of the
given objects) into a string of the form "<pre><list1>, <list2>,
... , <listn-1><conj> <listn><post>" and wordwrap it nicely onto
one or more lines.
The result is returned (note that it will end in a newline), at
least an empty string "".
Defaults are: "" for <pre>, "." for <post> and " and" for <conj>
EXAMPLE
implode_list(({"Foo", "Bar"})) -> "Foo and Bar.\n"