Applies some "Canonical XML" rules to a document tree.
The rule differ slightly for canonical XML and XPath in handling of comments
Note: This is not the whole canonicalization as it is specified by the W3C
Recommendation. Adding attribute defaults or sorting attributes in lexicographic
order is done by the transform function of module Text.XML.HXT.Validator.Validation.
Replacing entities or line feed normalization is done by the parser.
Rules: remove DTD parts, processing instructions, comments and substitute char refs in attribute values and text
Not implemented yet:
Whitespace within start and end tags is normalized
Special characters in attribute values and character content are replaced by character references