Portscanning

[kpcyrd]

@anthraxx requested port scanning since quite a while. The api I've been thinking about:

• portscan(ip, '80,443,22-23')
• the decision of syn-scan vs connect-scan is going to depend strongly on the operating system. For example we can probe for CAP_NET_RAW on linux and if detected use a syn-scan, while we probably have to use a regular connect scan everywhere else (unless sn0int is executed as root, which I don't think is a good idea)