use xmlrpc_encode instead of php_xmlrpc_encode
stop using xmlrpc_client

use curl and xmlrpc_encode_request/xmlrpc_decode_request,
and add the private method iSDK->call
remove $type parameter from iSDK phpdoc
drop XMLRPC library
only use xmlrpc_encode_request to encode the request

don't encode and decode like a maniac
return a new DateTime for infudate