#7 Add whitespace to pretty print XML.

[Eamonn O'Brien-Strain]

It would be nice to have the XML generated by toXml
have extra newlines and indentation to make human
reading easier. (Requested by Denis Bohm.)

There are problems with inserting whitespace in some
cases (for example within <pre> and other XHTML
elements) so maybe this should be a debug mode --
perhaps controlled by a JVM System.property