set display "Alive Hosts only" as default preference

[timmussche]

Would it not be better is this were the default option?
Every time I have used the scanner it was to find the IP or open port of an active device.
Not having the device in the active list logically concludes that the host is dead or not responding.
I get it that there should be an option to display the "dead" hosts too, but it is not logical to me that this is the default option.
After every installation I need to change the prefs to adjust for this, no big deal, but it bothers me.
Maybe others too?

[cbenjamin2009]

I agree with this pull request and support the idea of setting default option to live hosts only. I'm not looking for dead hosts either when using it!