Transfer long numbers over XMLRPC
Numeric parameters in ipalib were limited by XMLRPC boundaries for
integer (2^31-1) which is too low for some LDAP attributes like DNS
SOA serial field.
Transfer numbers which are not in XMLRPC boundary as a string and not
as a number to workaround this limitation. Int parameter had to be
updated to also accept Python's long type as valid int type.
https://fedorahosted.org/freeipa/ticket/2568