#485 [ide] XML Serializing discards white space in XML prolog

[Lukas Eder]

Although accepted by W3C specification (http://
www.w3.org/TR/2000/REC-xml-20001006#sec-prolog-dtd),
white space within the XML prolog are discarded by the
DOM parser, at parse-time. Hence, when serializing
XML, the information is lost.

This will require a work-around, probably in the
XMLInput class that manages a file's content.