#1 Allow non-standalone documents

[David Megginson]

From Sylvain Loiseau, 2005-01-07:

Another point (If i remember correcty) is the fact that
document outputed
with xml-writer contains a "standalone='yes'" flag in
the prolog. Perhaps
the content prolog, including the explicit or not
declaration of the
encoding, could be set as parameters by the user ?