public void setResolveEntityRefs(boolean resolve) {
        this.resolveEntityRefs = resolve;
    }
Lets subclasses get at the current format object, so they can call setTrimText, setNewLines, etc.
Put in to support the HTMLWriter, in the way
 that it pushes the current newline/trim state onto a stack and overrides
 the state within preformatted tags.
@return the output format
xmppserver/src/main/java/org/jivesoftware/util/XMLWriter.java