Added pcap dump functions which save packets as pcap file
Added pcap dump functions test
Added pcap dump feature to tcpdump example
Fixed return parameters in PcapLoop
Delted return in PcapDump, PcapDumpClose
Fixed return value name and error handling in PcapDumpFlush
Fixed return parameters in DumpOpen
Fixed loop structure in PcapLoop
Merge pull request #11 from khiro/support_pcap_dump

Added pcap dump functions which save packets as pcap file