Initializes the receiver with the XML contents encapsulated in a given data object.
Original signature is '- (id)initWithData:(NSData *)data'
Available in Mac OS X v10.3 and later.
- data (NSData)
- An NSData object containing XML markup.
An initialized NSXMLParser object or nil if an error occurs.
- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)