Add response for cat /bin/echo

[morgajp]

Added a working response to Mirai's cat /bin/echo command. Adding this response causes mirai to send a link to download the mirai malware, though the honeypot will not currently perform the download.

I had to make a change to the way commands are parsed because the honeypot needs to send actual 0x00 bytes, and not ascii strings '\x00'.

[charlie-the-unicorn]

Hi. Thanks for adding this.
Have you ever been able to receive any link?
I've run several tests and the scanner always leaves after the "applet not found" or the sessions times out. I am trying to understand if there's something wrong in the first response.

[morgajp]

Yes I have been able to receive links, what are you using for your configuration file?

[itamarsher]

Thanks for your contribution! I've merged your branch into master