v3.1

• Moved headers from the configuration file to a separate flag.
• Added graceful Ctrl+c handling. Second-order now saves the results it collected up to the point where it was killed before exiting.
• Reduced false-positives by checking for 404 status code or unregistered domains specifically, since that's how most of the takeover-able services behave.
• Made the stdout output more accurate and concise by printing the URLs that have not been visited only.