Constructor of the XML_Transformer class. It can be passed an associative array that may have the following keys:
caseFolding: If TRUE, XML attribute and element names will be case-folded.
caseFoldingTo: May be either CASE_UPPER or CASE_LOWER and sets the target case for the case-folding.
debug: May be either TRUE or FALSE, thus enabling or disabling complete debugging information. May also be an array containing the names of elements to which the generated debugging information shall be limited. The special keywords "&CDATA" and "&RECURSE" may be used to enable debugging information for CDATA and recursion events.
recursiveOperation: If TRUE, the transformation will continue recursively until the XML contains no more overloaded elements. Can be overrided on a per-element basis.
overloadedElements: Associative array with pre-defined set of overloaded elements.
overloadedNamespaces: Associative array with pre-defined set of overloaded elements.