Added "execCommand" support
Credit: https://github.com/micheloosterhof/kippo/
Merge branch 'pr/111' into review-pr-111

Conflicts:
	kippo.cfg.dist
	kippo/core/honeypot.py
when using execCommand, ls breaks without windowSize
code style changes
we don't need recvline.HistoricRecvLine for execCommand,
so branch off the protocol into two protocols
change exec handling so the command is allowed to run long enough for wget to
work
remove obsolete config entry