Handle CTRL+C and cleanup privileged sniffer pods

[bostrt]

This is partially addressing a few other issues:

• Addresses ctrl+c portion of #66

• Handling ctrl+c and calling cleanup: #131

• Addresses the issue in #130

• Address the issue except for lingering static-tcpdump processes in #53

Cleanup of the static-tcpdump process is going to need to be handled in another PR. I believe the only way to kill that process is to send a ctrl+c via the remotecommand/SPDY connection which is tricky (source) which is the workaround until this is resolved.

I'll also submit another PR for properly closing Wireshark upon a CTRL+C along with an option like --keep-wireshark to keep wireshark open after closing ksniff.

[bostrt]

@MichaelWasher would you mind reviewing this?

[Noksa]

@bostrt will it be released? It is not in 1.6.2 as I can see