Add passing XML generation test
Create empty arrays for contact details if not present, and add 'contacts' method to get all of them
Get xml root from class, not set manually
Automatically try to convert child objects to XML using our existing methods
Add XML serialisation options for collections
Automatically generate root tag from class name

Can be overridden if required
Define attribute lists for contact objects
Add ContactCollection object
Include contacts in attributes for person serialisation
Make Website inherit from Contact and remove url
Test serialisation of person contacts