Allow users to specify ports to scan in <IP>:<PORT> format

[felipewarrener]

The current input format assumes that you want to maintain a constant set of ports scanned across the entire range, but does not allow users to choose different ports for different hosts.

This means that if you complete a port scan of a range, and only a few individual hosts have a random port open, let's say 25000 for example, then you would need to opt to scan every single IP for 25000 which would then force you to try the VHOST on that port on every single host, hosts that you know don't even have that port open, with timeouts etc, it would make the tool unusable/infeasible for scanning large ranges.

There is no way to use this tool if you want to vary ports on IPs, I propose that you support this format of input, it would not conflict with the current input format as you could match for the colon character to distinguish when the user wants ports on a per-IP basis, it wouldn't require changing the networking code either, as either way you need to make one connection per port even if it's on the same host:

10.0.0.101:5190
10.0.0.102:8873
10.0.0.103:8222
10.0.0.104:443