add lookupnet() - fix for the issue #20 - reviewed by dugsong - from Joao Medeiros
add lookupnet() - fix for the issue #20 - reviewed by dugsong - from Joao Medeiros

fasguard/fasguard-pcap,FunctionAnalysis/pypcap,itxx00/pypcap,est/pypcap,est/pypcap,fasguard/fasguard-pcap,afghanistanyn/pypcap,afghanistanyn/pypcap,FunctionAnalysis/pypcap,pombreda/pypcap,itxx00/pypcap,pombreda/pypcap