Implement zilla dump command similar to tcpdump

[jfallows]

The Zilla runtime has a a pluggable command structure, currently used for start and stop.

./zilla
usage: zilla <command> [ <args> ]

Commands are:
    help    Display help information
    start   Start engine
    stop    Stop engine

See 'zilla help <command>' for more information on a specific command.

Add a new zilla dump command to produce a virtual packet capture of Zilla shared memory streams that can be dissected in Wireshark as tcp, tls, http, mqtt, amqp, etc.

Capturing the raw byte stream for each binding in zilla.json in .pcap format is sufficient to let Wireshark dissectors present the structured form of the protocol frames.

[bmaidics]

I'd like to take this one