tmp (wokkel.mam): cleaning and bug fix: - renamed MAMQueryRequest to MAMQuery - use of MAMQuery in queryArchive instead of separate arguments - fixed bad use of subprotocols.IQHandlerMixing.handleRequest - changed order of arguments in BuildForm to have more often used first - renamed parse to fromElement for coherency - added IMAMService interface - MAMService requestClass can be changed (it is specified in _request_class class attribute - use new-style classes where it make sense - MAMRequest.fromElement parse a <query/> parent instead of a <query/> directly