Nflog v5.5 - testing netlink socket buffer size

Hi Victor,
I reworked the code to fix the problem about netlink socket buffer size:
[31345] 7/4/2014 -- 11:50:31 - (source-nflog.c:265)  (ReceiveNFLOGThreadInit) -- [ERRCODE: SC_ERR_NFLOG_MAX_BUFSIZ(248)] - Maximum buffer size (10) in NFLOG has been reached

As done for ulogd2, if the buffer size is reached, it is doubled until the maximum buffer size is reached.