Record scanning parameters and total count of hosts scanned in the output file

[cweb]

This is a request to add the following information to in the XML output:

• Record the arguments passed to masscan
• Record the total count of hosts scanned

Right now masscan includes the following hosts info:

From my testing, the count of down isn't being used? For example, the above output was from a scan of 256 IP addresses, and a single port. I was expecting the total count to include "256" and the down count to be the difference, or "234".