Created XMLBuilder class & AlephRequestItem class
Also implemented building XML for HTML PUT action to request an item
Modified XML sample so it has an holdable item
Implemented GregorianCalendar convertor (to Aleph Date format)
Parsed all possible desired services
Implemented hold request URL build
Made AlephRequestItemService work (initiationHeader forwarding, patronId & itemId null check, updating responseData from passed AlephRequestItem)